Instinct

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Instinct

Instinct is the inherent inclination of a living organism towards a particular complex behaviour, containing innate (inborn) elements. The simplest example of an instinctive behaviour is a fixed action pattern (FAP), in which a very short to medium length sequence of actions, without variation, are carried out in response to a corresponding clearly defined stimulus. Every animal has instincts, including humans.

A loggerhead sea turtle hatchling makes its way to the open ocean.

Any behaviour is instinctive if it is performed without being based upon prior experience (that is, in the absence of learning), and is therefore an expression of innate biological factors. Sea turtles, newly hatched on a beach, will instinctively move toward the ocean. A marsupial climbs into its mother's pouch upon being born. Other examples include animal fighting, animal courtship behaviour, internal escape functions, and the building of nests. Though an instinct is defined by its invariant innate characteristics, details of its performance can be changed by experience; for example, a dog can improve its listening skills by practice.

A wet dog instinctively shakes the water from its fur.

Instincts are inborn complex patterns of behaviour that exist in most members of the species, and should be distinguished from reflexes, which are simple responses of an organism to a specific stimulus, such as the contraction of the pupil in response to bright light or the spasmodic movement of the lower leg when the knee is tapped. The absence of volitional capacity must not be confused with an inability to modify fixed action patterns. For example, people may be able to modify a stimulated fixed action pattern by consciously recognizing the point of its activation and simply stop doing it, whereas animals without a sufficiently strong volitional capacity may not be able to disengage from their fixed action patterns, once activated.

Early theorists

Initial studies

Primitive reflexes

Jean Henri Fabre (1823–1915) is said to be the first person to study small animals (other than birds) and insects, and he specifically specialized in the instincts of insects. Fabre considered an instinct to be a linked set of behaviours that an organism undergoes unconsciously in response to external conditions. Fabre concluded a significant difference between humans and other animals is that most animals cannot reason. He came to this conclusion after observing how insects and wild birds continued to repeat a certain behaviour in response to a novel situation. While these instinctive behaviours appeared complex, the insects and animals did not adjust their behaviour despite it not helping them in that novel situation. Fabre observed and labelled multiple behaviours "instinctive", for they do not involve reasoning, including maternal instincts; Metamorphosis; Mimicry; Molting; Playing dead; Taxis. Fabre believed instincts were "fixed patterns", meaning these linked sets of behaviours do not change in response to novel environmental situations. One specific example that helped him arrive at this conclusion is his study of various wasp species. All of the wasp species he studied performed a certain pattern of behaviour when catching their prey, which Fabre called a fixed pattern. Then Fabre intervened in the wasps' process of catching prey, and only one of the species adjusted their behaviour in response to this unfamiliar interception. Fabre explained this contradiction by arguing that any individuals which stray from the norms of their species are merely an exception, while also admitting that there could be some room for growth within a species' instincts. Fabre's belief that instincts are fixed opposes the theory of evolution. He rejected that one species could evolve into another, and also rejected that human consciousness could be achieved through the evolution of unconscious traits.

Wilhelm Wundt (1832–1920) founded the first psychology laboratory in 1879 at the University of Leipzig. He was able to draw conclusions about instinct from his careful observations of both animal and human behaviour. He believed unconscious processes (which he called "instinctive movements") were the result of sensations and emotions, and these unconscious processes were building blocks towards consciousness. Wundt studied the facial expressions babies made in response to the sensations of sweet, sour, and bitter tastes. He concluded these facial expressions were the result of the babies trying to avoid unpleasant emotions because there was something unpleasant in their mouths, and that these instincts (which he uses interchangeably with reflexive movements) only became innate because past generations learned it and it benefited their survival. The process by which Wundt explained the existence of instincts is natural selection. More specifically, his research suggests natural selection causes small changes in the nervous system over time. These changes bring about hereditary drives in organisms, which are then responsible for any unconscious processes. Another thing to note is that Wundt used the terms unconscious processes, reflexive movements, and instinctive movements interchangeably, often grouping them together.

Sigmund Freud considered that mental images of bodily needs, expressed in the form of mental desires, are called instincts. Freud defined instincts as "biological forces that motivate individuals to satisfy their needs." He divided them into life instincts (Eros), which are focused on survival, reproduction, and pleasure, and death instincts (Thanatos), which are associated with aggression and self-destruction. Freud emphasized the importance of these instincts in shaping human behavior and personality development.

In the early 20th century, there was recognized a "union of instinct and emotion". William McDougall held that many instincts have their respective associated specific emotions. As research became more rigorous and terms better defined, instinct as an explanation for human behaviour became less common. In 1932, McDougall argued that the word instinct is more suitable for describing animal behaviour, while he recommended the word propensity for goal-directed combinations of the many innate human abilities, which are loosely and variably linked, in a way that shows strong plasticity. McDougall defines instincts as "innate, inherited tendencies that guide behavior in a particular direction." He views instincts as the fundamental forces that influence human motivation and behavior. According to McDougall, instincts are biologically ingrained and provide the primary source of motivation for various human actions.

John B. Watson (1924) approached instincts from a behaviorist perspective, claiming that "instincts are complex, pre-programmed behaviors that can be conditioned into learned responses." While Watson acknowledges the existence of some innate behaviors, he argued that the majority of human behavior is learned through interaction with the environment, rather than being primarily driven by instinct.

In the 1950s, the psychologist Abraham Maslow argued that humans no longer have instincts because we have the ability to override them in certain situations. He felt that what is called instinct is often imprecisely defined, and really amounts to strong "drives". For Maslow, an instinct is something which cannot be overridden, and therefore while the term may have applied to humans in the past, it no longer does.

Innate behaviour revisited

An interest in innate behaviours reappeared in the 1950s with Konrad Lorenz and Nikolaas Tinbergen, who made the distinction between instinct and learned behaviours. Our modern understanding of instinctual behaviour in animals owes much to their work. For instance, there exists a sensitive period for a bird in which it learns the identity of its mother. Konrad Lorenz famously had a goose imprint on his boots. Thereafter the goose would follow whoever wore the boots. This suggests that the identity of the goose's mother was learned, but the goose's behaviour towards what it perceived as its mother was instinctive.

In a conference in 1960, chaired by the comparative psychologist Frank Beach, the term instinct was restricted in its application. During the 1960s and 1970s, textbooks still contained some discussion of instincts in reference to human behaviour. By the year 2000, a survey of the 12 best selling textbooks in introductory psychology revealed only one reference to instincts, and that was in regard to Sigmund Freud's referral to the "id" instincts. In this sense, the term instinct appeared to have become outmoded for introductory textbooks on human psychology. The book Instinct: An Enduring Problem in Psychology (1961) selected a range of writings about the topic.

In a classic paper published in 1972, the psychologist Richard Herrnstein wrote: "A comparison of McDougall's theory of instinct and Skinner's reinforcement theory—representing nature and nurture—shows remarkable, and largely unrecognized, similarities between the contending sides in the nature–nurture debate as applied to the analysis of behavior."

F. B. Mandal proposed a set of criteria by which a behaviour might be considered instinctual: (a) be automatic, (b) be irresistible, (c) occur at some point in development, (d) be triggered by some event in the environment, (e) occur in every member of the species, (f) be unmodifiable, and (g) govern behaviour for which the organism needs no training (although the organism may profit from experience and to that degree the behaviour is modifiable).

In Information Behavior: An Evolutionary Instinct (2010, pp. 35–42), Amanda Spink notes that "currently in the behavioral sciences instinct is generally understood as the innate part of behavior that emerges without any training or education in humans." She claims that the viewpoint that information behaviour has an instinctive basis is grounded in the latest thinking on human behaviour. Furthermore, she notes that "behaviors such as cooperation, sexual behavior, child rearing and aesthetics are [also] seen as 'evolved psychological mechanisms' with an instinctive basis." Spink adds that Steven Pinker similarly asserts that language acquisition is instinctive in humans in his book The Language Instinct (1994). In 1908, William McDougall wrote about the "instinct of curiosity" and its associated "emotion of wonder", though Spink's book does not mention this.

M. S. Blumberg in 2017 examined the use of the word instinct, finding that it varied significantly.

In humans

Main article: Human nature

Among possible examples of instinct-influenced behaviour in humans are the following.

1. Congenital preparedness for developing fear of snakes and spiders was found in six-month-old babies.
2. Infant cry is believed to be a manifestation of instinct. The infant cannot otherwise protect itself for survival during its long period of maturation. The maternal and paternal bond manifest particularly in response to the infant cry. Its mechanism has been partly elucidated by observations with functional MRI of the parent's brain.
3. The herd instinct is found in human children and chimpanzee infants, but is apparently absent in the young orangutans.
4. Hormones are linked to specific forms of human behaviour, such as sexuality. High levels of testosterone are often associated in a person (male or female) with aggressiveness.Decrease in testosterone level after the birth of a child was found among fathers.
5. Hygiene behaviour in humans was suggested to be partly instinctive, based on emotions such as disgust.
6. Maternal bond or maternal instinct is when a mother develops a relationship to a child to provide for its well-being. Maternal oxytocin is the hormone and neuropeptide thought to be responsible for predisposing women to showing bonding behavior and bonding.
7. Self-preservation in people generally is when they have the instinct to survive.
8. Fight-or-flight response in human beings has been said to be a particular response to the arising harmful event, attack or threat to survival.
9. Cooperation or social instinct has been postulated as an instinct necessary for the future survival of people.
10. Resistance towards change is the difficulty experienced by a person when they are trying to push against the suggestions made to change behavior or accept certain treatments regardless of whether it will improve their condition or not.
11. Adaptive behaviour to environment is an inherited innate phenotypic characteristic, whether inherited as instincts intricately, or as a neuropsychological capacity that furthers learning. Examples are mating, searching for food, situational awareness, establishing the pecking order and vocalizations.

Reflexes

Main article: Reflex

Examples of behaviours that do not require thought include many reflexes. The stimulus in a reflex may not require brain activity but instead may travel to the spinal cord as a message that is then transmitted back through the body, tracing a path called the reflex arc. Reflexes are similar to fixed action patterns in that most reflexes meet the criteria of a fixed action pattern. However, a fixed action pattern can be processed in the brain as well; a male stickleback's instinctive aggression towards anything red during his mating season is such an example. Examples of instinctive behaviours in humans include many of the primitive reflexes, such as rooting and suckling, behaviours which are present in mammals. In rats, it has been observed that innate responses are related to specific chemicals, and these chemicals are detected by two organs located in the nose: the vomeronasal organ (VNO) and the main olfactory epithelium (MOE).

Maturational

Some instinctive behaviours depend on maturational processes to appear. For instance, we commonly refer to birds "learning" to fly. However, young birds have been experimentally reared in devices that prevent them from moving their wings until they reached the age at which their cohorts were flying. These birds flew immediately and normally when released, showing that their improvement resulted from neuromuscular maturation and not true learning.

In evolution

Imprinting provides one example of instinct. This complex response may involve visual, auditory, and olfactory cues in the environment surrounding an organism. In some cases, imprinting attaches an offspring to its parent, which is a reproductive benefit to offspring survival. If an offspring has attachment to a parent, it is more likely to stay nearby under parental protection. Attached offspring are also more likely to learn from a parental figure when interacting closely. (Reproductive benefits are a driving force behind natural selection.)

Environment is an important factor in the evolution of innate behaviour. A hypothesis of Michael McCollough, a positive psychologist, explains that environment plays a key role in human behaviours such as forgiveness and revenge. This hypothesis theorizes that various social environments cause either forgiveness or revenge to prevail. McCollough relates his theory to game theory. In a tit-for-tat strategy, cooperation and retaliation are comparable to forgiveness and revenge. The choice between the two can be beneficial or detrimental, depending on what the partner-organism chooses. Though this psychological example of game theory does not have such directly measurable results, it provides an interesting theory of unique thought. From a more biological standpoint, the brain's limbic system operates as the main control-area for response to certain stimuli, including a variety of instinctual behaviour. The limbic system processes external stimuli related to emotions, social activity, and motivation, which propagates a behavioural response. Some behaviours include maternal care, aggression, defense, and social hierarchy. These behaviours are influenced by sensory input—sight, sound, touch, and smell.

Within the circuitry of the limbic system, there are various places where evolution could have taken place, or could take place in the future. For example, many rodents have receptors in the vomeronasal organ that respond explicitly to predator stimuli that specifically relate to that individual species of rodent. The reception of a predatory stimulus usually creates a response of defense or fear. Mating in rats follows a similar mechanism. The vomeronasal organ and the main olfactory epithelium, together called the olfactory system, detect pheromones from the opposite sex. These signals then travel to the medial amygdala, which disperses the signal to a variety of brain parts. The pathways involved with innate circuitry are extremely specialized and specific. Various organs and sensory receptors play parts in this complex process.

Instinct is a phenomenon that can be investigated from a multitude of angles: genetics, limbic system, nervous pathways, and environment. Researchers can study levels of instincts, from molecular to groups of individuals. Extremely specialized systems have evolved, resulting in individuals which exhibit behaviours without learning them.

Innatism

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Innatism

In the philosophy of mind, innatism is the view that the mind is born with already-formed ideas, knowledge, and beliefs. The opposing doctrine, that the mind is a tabula rasa (blank slate) at birth and all knowledge is gained from experience and the senses, is called empiricism.

Difference from nativism

Main article: Psychological nativism

Innatism and nativism are generally synonymous terms referring to the notion of preexisting ideas in the mind. However, more specifically, innatism refers to the philosophy of Descartes, who assumed that God or a similar being or process placed innate ideas and principles in the human mind. The innatist principles in this regard may overlap with similar concepts such as natural order and state of nature, in philosophy.

Nativism represents an adaptation of this, grounded in the fields of genetics, cognitive psychology, and psycholinguistics. Nativists hold that innate beliefs are in some way genetically programmed in our mind—they are the phenotypes of certain genotypes that all humans share in common. Nativism is a modern view rooted in innatism. The advocates of nativism are mainly philosophers who also work in the field of cognitive psychology or psycholinguistics: most notably Noam Chomsky and Jerry Fodor (although the latter adopted a more critical attitude toward nativism in his later writings).^{[citation needed]} The nativist's general objection against empiricism is still the same as was raised by the rationalists; the human mind of a newborn child is not a tabula rasa but is equipped with an inborn structure.

History

Although individual human beings vary in many ways (culturally, ethnically, linguistically, and so on), innate ideas are the same for everyone everywhere. For example, the philosopher René Descartes theorized that knowledge of God is innate in everybody. Philosophers such as Descartes and Plato were rationalists. Other philosophers, most notably the empiricists, were critical of innate ideas and denied they existed. The debate over innate ideas is central to the conflict between rationalists (who believe certain ideas exist independently of experience) and empiricists (who believe knowledge is derived from experience). Many believe the German philosopher Immanuel Kant synthesized these two early modern traditions in his philosophical thought.

Plato

Plato argues that if there are certain concepts that we know to be true but did not learn from experience, then it must be because we have an innate knowledge of it and that this knowledge must have been gained before birth. In Plato's Meno, he recalls a situation where his mentor Socrates questioned a slave boy about geometry. Though the slave boy had no previous experience with geometry, he was able to answer correctly. Plato reasoned that this was possible because Socrates' questions sparked the innate knowledge of math the boy had from birth.

René Descartes

Descartes (1596–1650) conveys the idea that innate knowledge or ideas is something inborn such as one would say, that a certain disease might be 'innate' to signify that a person might be at risk of contracting such a disease. He suggests that something that is 'innate' is effectively present from birth and while it may not reveal itself then, is more than likely to present itself later in life. Descartes’ comparison of innate knowledge to an innate disease, whose symptoms may show up only later in life, unless prohibited by a factor like age or puberty, suggests that if an event occurs prohibiting someone from exhibiting an innate behaviour or knowledge, it doesn't mean the knowledge did not exist at all but rather it wasn't expressed – they were not able to acquire that knowledge. In other words, innate beliefs, ideas and knowledge require experiences to be triggered or they may never be expressed. Experiences are not the source of knowledge as proposed by John Locke, but catalysts to the uncovering of knowledge.

Gottfried Wilhelm Leibniz

Gottfried Wilhelm Leibniz (1646–1716) contends that we are born with certain innate ideas, the most identifiable of these being mathematical truisms. The idea that 1 + 1 = 2 is evident to us without the necessity for empirical evidence. Leibniz argues that empiricism can show us that concepts are true in the present; the observation of one apple and then another in one instance, and in that instance only, leads to the conclusion that one and another equals two. However, the suggestion that one and another will always equal two requires an innate idea, as that would be a suggestion of things unwitnessed.

Leibniz called such concepts as mathematical truisms "necessary truths". Another example of such may be the phrase, "What is, is" or "It is impossible for the same thing to be and not to be". Leibniz argues that such truisms are universally assented to (acknowledged by all to be true); this being the case, it must be due to their status as innate ideas. Often some ideas are acknowledged as necessarily true but are not universally assented to. Leibniz would suggest that this is simply because the person in question has not become aware of the innate idea, not because they do not possess it. Leibniz argues that empirical evidence can serve to bring to the surface certain principles that are already innately embedded in our minds. This is similar to needing to hear only the first few notes to recall the rest of the melody.

John Locke

The main antagonist to the concept of innate ideas is John Locke (1632–1704), a contemporary of Leibniz. Locke argued that the mind is in fact devoid of all knowledge or ideas at birth; it is a blank sheet or tabula rasa. He argued that all our ideas are constructed in the mind via a process of constant composition and decomposition of the input that we receive through our senses. Locke, in An Essay Concerning Human Understanding, which he published in 1690 under his own name, contends that the concept of universal assent, in fact, proves nothing, except perhaps that everyone is in agreement. In short universal assent proves that there is universal assent and nothing else. Locke goes on to suggest that, in fact, there is no universal assent. Even a phrase such as "What is, is" is not universally assented to; infants and severely mentally disabled adults do not generally acknowledge this truism. Locke also attacks the idea that an innate idea can be imprinted on the mind without the owner realizing it. For Locke, such reasoning would allow one to conclude the absurd: "All the Truths a Man ever comes to know, will, by this account, be, every one of them, innate." To return to the musical analogy, we may not be able to recall the entire melody until we hear the first few notes, but we were aware of the fact that we knew the melody and that upon hearing the first few notes we would be able to recall the rest.

Locke ends his attack on innate ideas by arguing that the mind is a tabula rasa or "blank slate", and that all ideas come from experience. All our knowledge is founded in sensory experience. Essentially, the same knowledge thought to be a priori by Leibniz is, according to Locke, the result of empirical knowledge, which has a lost origin [been forgotten] in respect to the inquirer. However, the inquirer is not cognizant of this fact; thus, he experiences what he believes to be a priori knowledge.

1. The theory of innate knowledge is excessive. Even innatists accept that most of our knowledge is learned through experience, but if that can be extended to account for all knowledge, we learn color through seeing it, so therefore, there is no need for a theory about an innate understanding of color.
2. No ideas are universally held. Do we all possess the idea of God? Do we all believe in justice and beauty? Do we all understand the law of identity? If not, it may not be the case that we have acquired these ideas through impressions/experience/social interaction.
3. Even if there are some universally agreed statements, it is just the ability of the human brain to organize learned ideas/words, that is, innate. An "ability to organize" is not the same as "possessing propositional knowledge" (e.g., a computer with no saved files has all the operations programmed in but has an empty memory).

Noam Chomsky

In his Meno, Plato raises an important epistemological quandary: how is it that we have certain ideas that are not conclusively derivable from our environments? Linguistics scholar Noam Chomsky (born 1928) has taken this problem as a philosophical framework for the scientific inquiry into innatism. His linguistic theory, which derives from 18th-century classical-liberal thinkers such as Wilhelm von Humboldt (1767–1835), attempts to explain in cognitive terms how we can develop knowledge of systems which are said, by supporters of innatism, to be too rich and complex to be derived from our environment.

It is claimed one such example is our linguistic faculty. According to Chomsky, our linguistic systems contain a systemic complexity which supposedly could not be empirically derived: the environment seems too poor, variable and indeterminate, to explain the extraordinary ability to learn complex concepts possessed by very young children. Essentially, their accurate grammatical knowledge cannot have originated from their experiences as their experiences are not adequate. It follows that humans must be born with a universal innate grammar, which is determinate and has a highly organized directive component, and enables the language learner to ascertain and categorize language heard into a system. Chomsky contends that the ability to learn how to properly construct sentences or know which sentences are grammatically incorrect is an ability gained from innate knowledge. Noam Chomsky cites as evidence for this theory, the apparent invariability, according to his views, of human languages at a fundamental level. In this way, linguistics may provide a window into the human mind, and establish scientific theories of innateness which otherwise would remain merely speculative.

One implication of Chomsky's innatism, if correct, is that at least a part of human knowledge consists in cognitive predispositions, which are triggered and developed by the environment, but not determined by it. Chomsky suggests that we can look at how a belief is acquired as an input-output situation. He supports the doctrine of innatism as he states that human beliefs gathered from sensory experience are much richer and complex than the experience itself. He asserts that the extra information gathered is from the mind itself as it cannot solely be from experiences. Humans derive excess amount of information from their environment so some of that information must be pre-determined.

Empiricism

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Empiricism

In philosophy, empiricism is an epistemological view which holds that true knowledge or justification comes either only or primarily from sensory experience and empirical evidence. It is one of several competing views within epistemology, along with rationalism and skepticism. Empiricists argue that empiricism is a more reliable method of finding the truth than relying purely on logical reasoning, because humans have cognitive biases and limitations which lead to errors of judgement.

Empiricism emphasizes the central role of empirical evidence in the formation of ideas, rather than innate ideas or traditions. Empiricists may argue that traditions (or customs) arise due to relations of previous sensory experiences. Historically, empiricism was associated with the "blank slate" concept (tabula rasa), according to which the human mind is "blank" at birth and develops its thoughts only through later experience.

Empiricism in the philosophy of science emphasizes evidence, especially as discovered in experiments. It is a fundamental part of the scientific method that all hypotheses and theories must be tested against observations of the natural world rather than resting solely on a priori reasoning, intuition, or revelation. Empiricism, often used by natural scientists, holds that "knowledge is based on experience" and that "knowledge is tentative and probabilistic, subject to continued revision and falsification". Empirical research, including experiments and validated measurement tools, guides the scientific method.

Etymology

The English term empirical derives from the Ancient Greek word ἐμπειρία, empeiria, which is cognate with and translates to the Latin experientia, from which the words experience and experiment are derived.

Background

Main article: Empirical method

A central concept in science and the scientific method is that conclusions must be empirically based on the evidence of the senses. Both natural and social sciences use working hypotheses that are testable by observation and experiment. The term semi-empirical is sometimes used to describe theoretical methods that make use of basic axioms, established scientific laws, and previous experimental results to engage in reasoned model building and theoretical inquiry.

Philosophical empiricists hold no knowledge to be properly inferred or deduced unless it is derived from one's sense-based experience. In epistemology (theory of knowledge) empiricism is typically contrasted with rationalism, which holds that knowledge may be derived from reason independently of the senses, and in the philosophy of mind it is often contrasted with innatism, which holds that some knowledge and ideas are already present in the mind at birth. However, many Enlightenment rationalists and empiricists still made concessions to each other. For example, the empiricist John Locke admitted that some knowledge (e.g. knowledge of God's existence) could be arrived at through intuition and reasoning alone. Similarly, Robert Boyle, a prominent advocate of the experimental method, held that we also have innate ideas. At the same time, the main continental rationalists (Descartes, Spinoza, and Leibniz) were also advocates of the empirical "scientific method".

History

Early empiricism

Aristotle

Between 600 and 200 BCE, the Vaisheshika school of Hindu philosophy, founded by the ancient Indian philosopher Kanada, accepted perception and inference as the only two reliable sources of knowledge. This is enumerated in his work Vaiśeṣika Sūtra. The Charvaka school held similar beliefs, asserting that perception is the only reliable source of knowledge while inference obtains knowledge with uncertainty.

The earliest Western proto-empiricists were the empiric school of ancient Greek medical practitioners, founded in 330 BCE. Its members rejected the doctrines of the dogmatic school, preferring to rely on the observation of phantasiai (i.e., phenomena, the appearances). The Empiric school was closely allied with the Pyrrhonist school of philosophy, which made the philosophical case for their proto-empiricism.

The notion of tabula rasa ("clean slate" or "blank tablet") connotes a view of the mind as an originally blank or empty recorder (Locke used the words "white paper") on which experience leaves marks. This denies that humans have innate ideas. The notion dates back to Aristotle, c. 350 BC:

What the mind (nous) thinks must be in it in the same sense as letters are on a tablet (grammateion) which bears no actual writing (grammenon); this is just what happens in the case of the mind. (Aristotle, On the Soul, 3.4.430^a1).

Aristotle's explanation of how this was possible was not strictly empiricist in a modern sense, but rather based on his theory of potentiality and actuality, and experience of sense perceptions still requires the help of the active nous. These notions contrasted with Platonic notions of the human mind as an entity that pre-existed somewhere in the heavens, before being sent down to join a body on Earth (see Plato's Phaedo and Apology, as well as others). Aristotle was considered to give a more important position to sense perception than Plato, and commentators in the Middle Ages summarized one of his positions as "nihil in intellectu nisi prius fuerit in sensu" (Latin for "nothing in the intellect without first being in the senses").

This idea was later developed in ancient philosophy by the Stoic school, from about 330 BCE. Stoic epistemology generally emphasizes that the mind starts blank, but acquires knowledge as the outside world is impressed upon it. The doxographer Aetius summarizes this view as "When a man is born, the Stoics say, he has the commanding part of his soul like a sheet of paper ready for writing upon."

A drawing of Ibn Sina (Avicenna) from 1271

Islamic Golden Age and Pre-Renaissance (5th to 15th centuries CE)

See also: Islamic philosophy

During the Middle Ages (from the 5th to the 15th century CE) Aristotle's theory of tabula rasa was developed by Islamic philosophers starting with Al Farabi (c. 872 – c. 951 CE), developing into an elaborate theory by Avicenna (c. 980 – 1037 CE) and demonstrated as a thought experiment by Ibn Tufail. For Avicenna (Ibn Sina), for example, the tabula rasa is a pure potentiality that is actualized through education, and knowledge is attained through "empirical familiarity with objects in this world from which one abstracts universal concepts" developed through a "syllogistic method of reasoning in which observations lead to propositional statements which when compounded lead to further abstract concepts". The intellect itself develops from a material intellect (al-'aql al-hayulani), which is a potentiality "that can acquire knowledge to the active intellect (al-'aql al-fa'il), the state of the human intellect in conjunction with the perfect source of knowledge". So the immaterial "active intellect", separate from any individual person, is still essential for understanding to occur.

In the 12th century CE, the Andalusian Muslim philosopher and novelist Abu Bakr Ibn Tufail (known as "Abubacer" or "Ebu Tophail" in the West) included the theory of tabula rasa as a thought experiment in his Arabic philosophical novel, Hayy ibn Yaqdhan in which he depicted the development of the mind of a feral child "from a tabula rasa to that of an adult, in complete isolation from society" on a desert island, through experience alone. The Latin translation of his philosophical novel, entitled Philosophus Autodidactus, published by Edward Pococke the Younger in 1671, had an influence on John Locke's formulation of tabula rasa in An Essay Concerning Human Understanding.

A similar Islamic theological novel, Theologus Autodidactus, was written by the Arab theologian and physician Ibn al-Nafis in the 13th century. It also dealt with the theme of empiricism through the story of a feral child on a desert island, but departed from its predecessor by depicting the development of the protagonist's mind through contact with society rather than in isolation from society.

During the 13th century Thomas Aquinas adopted into scholasticism the Aristotelian position that the senses are essential to the mind. Bonaventure (1221–1274), one of Aquinas' strongest intellectual opponents, offered some of the strongest arguments in favour of the Platonic idea of the mind.

Renaissance Italy

See also: Italian Renaissance and Italian philosophy

In the late renaissance various writers began to question the medieval and classical understanding of knowledge acquisition in a more fundamental way. In political and historical writing Niccolò Machiavelli and his friend Francesco Guicciardini initiated a new realistic style of writing. Machiavelli in particular was scornful of writers on politics who judged everything in comparison to mental ideals and demanded that people should study the "effectual truth" instead. Their contemporary, Leonardo da Vinci (1452–1519) said, "If you find from your own experience that something is a fact and it contradicts what some authority has written down, then you must abandon the authority and base your reasoning on your own findings."

Significantly, an empirical metaphysical system was developed by the Italian philosopher Bernardino Telesio which had an enormous impact on the development of later Italian thinkers, including Telesio's students Antonio Persio and Sertorio Quattromani, his contemporaries Thomas Campanella and Giordano Bruno, and later British philosophers such as Francis Bacon, who regarded Telesio as "the first of the moderns". Telesio's influence can also be seen on the French philosophers René Descartes and Pierre Gassendi.

The decidedly anti-Aristotelian and anti-clerical music theorist Vincenzo Galilei (c. 1520 – 1591), father of Galileo and the inventor of monody, made use of the method in successfully solving musical problems, firstly, of tuning such as the relationship of pitch to string tension and mass in stringed instruments, and to volume of air in wind instruments; and secondly to composition, by his various suggestions to composers in his Dialogo della musica antica e moderna (Florence, 1581). The Italian word he used for "experiment" was esperimento. It is known that he was the essential pedagogical influence upon the young Galileo, his eldest son (cf. Coelho, ed. Music and Science in the Age of Galileo Galilei), arguably one of the most influential empiricists in history. Vincenzo, through his tuning research, found the underlying truth at the heart of the misunderstood myth of 'Pythagoras' hammers' (the square of the numbers concerned yielded those musical intervals, not the actual numbers, as believed), and through this and other discoveries that demonstrated the fallibility of traditional authorities, a radically empirical attitude developed, passed on to Galileo, which regarded "experience and demonstration" as the sine qua non of valid rational enquiry.

British empiricism

Thomas Hobbes

British empiricism, a retrospective characterization, emerged during the 17th century as an approach to early modern philosophy and modern science. Although both integral to this overarching transition, Francis Bacon, in England, first advocated for empiricism in 1620 (in his Novum Organum), whereas René Descartes, in France, laid the main groundwork upholding rationalism in 1641 (in his Meditations on First Philosophy). (Bacon's natural philosophy was influenced by Italian philosopher Bernardino Telesio and by Swiss physician Paracelsus.) Contributing later in the 17th century, Thomas Hobbes and Baruch Spinoza are retrospectively identified likewise as an empiricist and a rationalist, respectively. In the Enlightenment of the late 17th century, John Locke in England, and in the 18th century, both George Berkeley in Ireland and David Hume in Scotland, all became leading exponents of empiricism, hence the dominance of empiricism in British philosophy. The distinction between rationalism and empiricism was not formally made until Immanuel Kant, in Germany, who sought to merge the two views in his Critique of Pure Reason (1781).

In response to the early-to-mid-17th-century "continental rationalism", John Locke (1632–1704) proposed in An Essay Concerning Human Understanding (1689) a very influential view wherein the only knowledge humans can have is a posteriori, i.e., based upon experience. Locke is famously attributed with holding the proposition that the human mind is a tabula rasa, a "blank tablet", in Locke's words "white paper", on which the experiences derived from sense impressions as a person's life proceeds are written.

There are two sources of our ideas: sensation and reflection. In both cases, a distinction is made between simple and complex ideas. The former are unanalysable, and are broken down into primary and secondary qualities. Primary qualities are essential for the object in question to be what it is. Without specific primary qualities, an object would not be what it is. For example, an apple is an apple because of the arrangement of its atomic structure. If an apple were structured differently, it would cease to be an apple. Secondary qualities are the sensory information we can perceive from its primary qualities. For example, an apple can be perceived in various colours, sizes, and textures but it is still identified as an apple. Therefore, its primary qualities dictate what the object essentially is, while its secondary qualities define its attributes. Complex ideas combine simple ones, and divide into substances, modes, and relations. According to Locke, our knowledge of things is a perception of ideas that are in accordance or discordance with each other, which is very different from the quest for certainty of Descartes.

George Berkeley

A generation later, the Irish Anglican bishop George Berkeley (1685–1753) determined that Locke's view immediately opened a door that would lead to eventual atheism. In response to Locke, he put forth in his Treatise Concerning the Principles of Human Knowledge (1710) an important challenge to empiricism in which things only exist either as a result of their being perceived, or by virtue of the fact that they are an entity doing the perceiving. (For Berkeley, God fills in for humans by doing the perceiving whenever humans are not around to do it.) In his text Alciphron, Berkeley maintained that any order humans may see in nature is the language or handwriting of God. Berkeley's approach to empiricism would later come to be called subjective idealism.

Scottish philosopher David Hume (1711–1776) responded to Berkeley's criticisms of Locke, as well as other differences between early modern philosophers, and moved empiricism to a new level of skepticism. Hume argued in keeping with the empiricist view that all knowledge derives from sense experience, but he accepted that this has implications not normally acceptable to philosophers. He wrote for example, "Locke divides all arguments into demonstrative and probable. On this view, we must say that it is only probable that all men must die or that the sun will rise to-morrow, because neither of these can be demonstrated. But to conform our language more to common use, we ought to divide arguments into demonstrations, proofs, and probabilities—by ‘proofs’ meaning arguments from experience that leave no room for doubt or opposition." And,

I believe the most general and most popular explication of this matter, is to say [See Mr. Locke, chapter of power.], that finding from experience, that there are several new productions in matter, such as the motions and variations of body, and concluding that there must somewhere be a power capable of producing them, we arrive at last by this reasoning at the idea of power and efficacy. But to be convinced that this explication is more popular than philosophical, we need but reflect on two very obvious principles. First, That reason alone can never give rise to any original idea, and secondly, that reason, as distinguished from experience, can never make us conclude, that a cause or productive quality is absolutely requisite to every beginning of existence. Both these considerations have been sufficiently explained: and therefore shall not at present be any farther insisted on.

— Hume, Section XIV, "Of the idea of necessary connexion", in A Treatise of Human Nature

Hume divided all of human knowledge into two categories: relations of ideas and matters of fact (see also Kant's analytic-synthetic distinction). Mathematical and logical propositions (e.g. "that the square of the hypotenuse is equal to the sum of the squares of the two sides") are examples of the first, while propositions involving some contingent observation of the world (e.g. "the sun rises in the East") are examples of the second. All of people's "ideas", in turn, are derived from their "impressions". For Hume, an "impression" corresponds roughly with what we call a sensation. To remember or to imagine such impressions is to have an "idea". Ideas are therefore the faint copies of sensations.

David Hume's empiricism led to numerous philosophical schools.

Hume maintained that no knowledge, even the most basic beliefs about the natural world, can be conclusively established by reason. Rather, he maintained, our beliefs are more a result of accumulated habits, developed in response to accumulated sense experiences. Among his many arguments Hume also added another important slant to the debate about scientific method—that of the problem of induction. Hume argued that it requires inductive reasoning to arrive at the premises for the principle of inductive reasoning, and therefore the justification for inductive reasoning is a circular argument. Among Hume's conclusions regarding the problem of induction is that there is no certainty that the future will resemble the past. Thus, as a simple instance posed by Hume, we cannot know with certainty by inductive reasoning that the sun will continue to rise in the East, but instead come to expect it to do so because it has repeatedly done so in the past.

Hume concluded that such things as belief in an external world and belief in the existence of the self were not rationally justifiable. According to Hume these beliefs were to be accepted nonetheless because of their profound basis in instinct and custom. Hume's lasting legacy, however, was the doubt that his skeptical arguments cast on the legitimacy of inductive reasoning, allowing many skeptics who followed to cast similar doubt.

Phenomenalism

Main article: Phenomenalism

Most of Hume's followers have disagreed with his conclusion that belief in an external world is rationally unjustifiable, contending that Hume's own principles implicitly contained the rational justification for such a belief, that is, beyond being content to let the issue rest on human instinct, custom and habit. According to an extreme empiricist theory known as phenomenalism, anticipated by the arguments of both Hume and George Berkeley, a physical object is a kind of construction out of our experiences.

Phenomenalism is the view that physical objects, properties, events (whatever is physical) are reducible to mental objects, properties, events. Ultimately, only mental objects, properties, events, exist—hence the closely related term subjective idealism. By the phenomenalistic line of thinking, to have a visual experience of a real physical thing is to have an experience of a certain kind of group of experiences. This type of set of experiences possesses a constancy and coherence that is lacking in the set of experiences of which hallucinations, for example, are a part. As John Stuart Mill put it in the mid-19th century, matter is the "permanent possibility of sensation". Mill's empiricism went a significant step beyond Hume in still another respect: in maintaining that induction is necessary for all meaningful knowledge including mathematics. As summarized by D.W. Hamlin:

[Mill] claimed that mathematical truths were merely very highly confirmed generalizations from experience; mathematical inference, generally conceived as deductive [and a priori] in nature, Mill set down as founded on induction. Thus, in Mill's philosophy there was no real place for knowledge based on relations of ideas. In his view logical and mathematical necessity is psychological; we are merely unable to conceive any other possibilities than those that logical and mathematical propositions assert. This is perhaps the most extreme version of empiricism known, but it has not found many defenders.

Mill's empiricism thus held that knowledge of any kind is not from direct experience but an inductive inference from direct experience. The problems other philosophers have had with Mill's position center around the following issues: Firstly, Mill's formulation encounters difficulty when it describes what direct experience is by differentiating only between actual and possible sensations. This misses some key discussion concerning conditions under which such "groups of permanent possibilities of sensation" might exist in the first place. Berkeley put God in that gap; the phenomenalists, including Mill, essentially left the question unanswered.

In the end, lacking an acknowledgement of an aspect of "reality" that goes beyond mere "possibilities of sensation", such a position leads to a version of subjective idealism. Questions of how floor beams continue to support a floor while unobserved, how trees continue to grow while unobserved and untouched by human hands, etc., remain unanswered, and perhaps unanswerable in these terms.^[29][36] Secondly, Mill's formulation leaves open the unsettling possibility that the "gap-filling entities are purely possibilities and not actualities at all". Thirdly, Mill's position, by calling mathematics merely another species of inductive inference, misapprehends mathematics. It fails to fully consider the structure and method of mathematical science, the products of which are arrived at through an internally consistent deductive set of procedures which do not, either today or at the time Mill wrote, fall under the agreed meaning of induction.

The phenomenalist phase of post-Humean empiricism ended by the 1940s, for by that time it had become obvious that statements about physical things could not be translated into statements about actual and possible sense data. If a physical object statement is to be translatable into a sense-data statement, the former must be at least deducible from the latter. But it came to be realized that there is no finite set of statements about actual and possible sense-data from which we can deduce even a single physical-object statement. The translating or paraphrasing statement must be couched in terms of normal observers in normal conditions of observation.

There is, however, no finite set of statements that are couched in purely sensory terms and can express the satisfaction of the condition of the presence of a normal observer. According to phenomenalism, to say that a normal observer is present is to make the hypothetical statement that were a doctor to inspect the observer, the observer would appear to the doctor to be normal. But, of course, the doctor himself must be a normal observer. If we are to specify this doctor's normality in sensory terms, we must make reference to a second doctor who, when inspecting the sense organs of the first doctor, would himself have to have the sense data a normal observer has when inspecting the sense organs of a subject who is a normal observer. And if we are to specify in sensory terms that the second doctor is a normal observer, we must refer to a third doctor, and so on (also see the third man).

Logical empiricism

Main article: Logical positivism

Logical empiricism (also logical positivism or neopositivism) was an early 20th-century attempt to synthesize the essential ideas of British empiricism (e.g. a strong emphasis on sensory experience as the basis for knowledge) with certain insights from mathematical logic that had been developed by Gottlob Frege and Ludwig Wittgenstein. Some of the key figures in this movement were Otto Neurath, Moritz Schlick and the rest of the Vienna Circle, along with A. J. Ayer, Rudolf Carnap and Hans Reichenbach.

The neopositivists subscribed to a notion of philosophy as the conceptual clarification of the methods, insights and discoveries of the sciences. They saw in the logical symbolism elaborated by Frege (1848–1925) and Bertrand Russell (1872–1970) a powerful instrument that could rationally reconstruct all scientific discourse into an ideal, logically perfect, language that would be free of the ambiguities and deformations of natural language. This gave rise to what they saw as metaphysical pseudoproblems and other conceptual confusions. By combining Frege's thesis that all mathematical truths are logical with the early Wittgenstein's idea that all logical truths are mere linguistic tautologies, they arrived at a twofold classification of all propositions: the "analytic" (a priori) and the "synthetic" (a posteriori). On this basis, they formulated a strong principle of demarcation between sentences that have sense and those that do not: the so-called "verification principle". Any sentence that is not purely logical, or is unverifiable, is devoid of meaning. As a result, most metaphysical, ethical, aesthetic and other traditional philosophical problems came to be considered pseudoproblems.

In the extreme empiricism of the neopositivists—at least before the 1930s—any genuinely synthetic assertion must be reducible to an ultimate assertion (or set of ultimate assertions) that expresses direct observations or perceptions. In later years, Carnap and Neurath abandoned this sort of phenomenalism in favor of a rational reconstruction of knowledge into the language of an objective spatio-temporal physics. That is, instead of translating sentences about physical objects into sense-data, such sentences were to be translated into so-called protocol sentences, for example, "X at location Y and at time T observes such and such". The central theses of logical positivism (verificationism, the analytic–synthetic distinction, reductionism, etc.) came under sharp attack after World War II by thinkers such as Nelson Goodman, W. V. Quine, Hilary Putnam, Karl Popper, and Richard Rorty. By the late 1960s, it had become evident to most philosophers that the movement had pretty much run its course, though its influence is still significant among contemporary analytic philosophers such as Michael Dummett and other anti-realists.

Pragmatism

In the late 19th and early 20th century, several forms of pragmatic philosophy arose. The ideas of pragmatism, in its various forms, developed mainly from discussions between Charles Sanders Peirce and William James when both men were at Harvard in the 1870s. James popularized the term "pragmatism", giving Peirce full credit for its patrimony, but Peirce later demurred from the tangents that the movement was taking, and redubbed what he regarded as the original idea with the name of "pragmaticism". Along with its pragmatic theory of truth, this perspective integrates the basic insights of empirical (experience-based) and rational (concept-based) thinking.

Charles Sanders Peirce

Charles Peirce (1839–1914) was highly influential in laying the groundwork for today's empirical scientific method. Although Peirce severely criticized many elements of Descartes' peculiar brand of rationalism, he did not reject rationalism outright. Indeed, he concurred with the main ideas of rationalism, most importantly the idea that rational concepts can be meaningful and the idea that rational concepts necessarily go beyond the data given by empirical observation. In later years he even emphasized the concept-driven side of the then ongoing debate between strict empiricism and strict rationalism, in part to counterbalance the excesses to which some of his cohorts had taken pragmatism under the "data-driven" strict-empiricist view.

Among Peirce's major contributions was to place inductive reasoning and deductive reasoning in a complementary rather than competitive mode, the latter of which had been the primary trend among the educated since David Hume wrote a century before. To this, Peirce added the concept of abductive reasoning. The combined three forms of reasoning serve as a primary conceptual foundation for the empirically based scientific method today. Peirce's approach "presupposes that (1) the objects of knowledge are real things, (2) the characters (properties) of real things do not depend on our perceptions of them, and (3) everyone who has sufficient experience of real things will agree on the truth about them. According to Peirce's doctrine of fallibilism, the conclusions of science are always tentative. The rationality of the scientific method does not depend on the certainty of its conclusions, but on its self-corrective character: by continued application of the method science can detect and correct its own mistakes, and thus eventually lead to the discovery of truth".

William James

In his Harvard "Lectures on Pragmatism" (1903), Peirce enumerated what he called the "three cotary propositions of pragmatism" (L: cos, cotis whetstone), saying that they "put the edge on the maxim of pragmatism". First among these, he listed the peripatetic-thomist observation mentioned above, but he further observed that this link between sensory perception and intellectual conception is a two-way street. That is, it can be taken to say that whatever we find in the intellect is also incipiently in the senses. Hence, if theories are theory-laden then so are the senses, and perception itself can be seen as a species of abductive inference, its difference being that it is beyond control and hence beyond critique—in a word, incorrigible. This in no way conflicts with the fallibility and revisability of scientific concepts, since it is only the immediate percept in its unique individuality or "thisness"—what the Scholastics called its haecceity—that stands beyond control and correction. Scientific concepts, on the other hand, are general in nature, and transient sensations do in another sense find correction within them. This notion of perception as abduction has received periodic revivals in artificial intelligence and cognitive science research, most recently for instance with the work of Irvin Rock on indirect perception.

Around the beginning of the 20th century, William James (1842–1910) coined the term "radical empiricism" to describe an offshoot of his form of pragmatism, which he argued could be dealt with separately from his pragmatism—though in fact the two concepts are intertwined in James's published lectures. James maintained that the empirically observed "directly apprehended universe needs ... no extraneous trans-empirical connective support", by which he meant to rule out the perception that there can be any value added by seeking supernatural explanations for natural phenomena. James' "radical empiricism" is thus not radical in the context of the term "empiricism", but is instead fairly consistent with the modern use of the term "empirical". His method of argument in arriving at this view, however, still readily encounters debate within philosophy even today.

John Dewey (1859–1952) modified James' pragmatism to form a theory known as instrumentalism. The role of sense experience in Dewey's theory is crucial, in that he saw experience as a unified totality of things through which everything else is interrelated. Dewey's basic thought, in accordance with empiricism, was that reality is determined by past experience. Therefore, humans adapt their past experiences of things to perform experiments upon and test the pragmatic values of such experience. The value of such experience is measured experientially and scientifically, and the results of such tests generate ideas that serve as instruments for future experimentation, in physical sciences as in ethics. Thus, ideas in Dewey's system retain their empiricist flavour in that they are only known a posteriori.

Empiricism in contemporary philosophy of mind and cognitive science

While empiricism has traditionally been an epistemological doctrine concerned with the sources and limits of human knowledge, it has also taken on a psychological dimension in contemporary philosophy of mind and cognitive science, where it stands in contrast with nativism (or rationalism) over the nature and origins of mental representations, concepts, and cognitive capacities. Contemporary empiricists hold that the mind's innate endowment is limited to relatively simple and general-purpose learning mechanisms and that the rich cognitive capacities humans display — including language acquisition, conceptual thought, and social cognition — can be explained without positing substantive innate mental content. Nativists (or rationalists), by contrast, argue that innate mental representations and specialized psychological mechanisms play a foundational role in explaining how the human mind acquires its knowledge and diverse cognitive capacities.