Legal scholars, economists, activists, policymakers, industries, and 
trade organizations have held differing views on patents and engaged in 
contentious debates on the subject. Critical perspectives emerged in the
 nineteenth century that were especially based on the principles of free trade.  Contemporary criticisms have echoed those arguments, claiming that 
patents block innovation and waste resources that could otherwise be 
used productively, and also block access to an increasingly important "commons" of enabling technologies (a phenomenon called the tragedy of the anticommons), apply a "one size fits all" model to industries with differing needs,
 that is especially unproductive for industries other than chemicals and
 pharmaceuticals and especially unproductive for the software industry.  Enforcement by patent trolls of poor quality patents has led to criticism of the patent office as well as the system itself.
  Patents on pharmaceuticals have also been a particular focus of 
criticism, as the high prices they enable puts life-saving drugs out of 
reach of many people.  Alternatives to patents have been proposed, such Joseph Stiglitz's suggestion of providing "prize money"
 (from a "prize fund" sponsored by the government) as a substitute for 
the lost profits associated with abstaining from the monopoly given by a
 patent.
These debates are part of a larger discourse on intellectual property protection which also reflects differing perspectives on copyright.
These debates are part of a larger discourse on intellectual property protection which also reflects differing perspectives on copyright.
History
Criticism
 of patents reached an early peak in Victorian Britain between 1850 and 
1880, in a campaign against patenting that expanded to target copyright too and, in the judgment of historian Adrian Johns,
 "remains to this day the strongest [campaign] ever undertaken against 
intellectual property", coming close to abolishing patents. Its most prominent activists - Isambard Kingdom Brunel, William Robert Grove, William Armstrong and Robert A. MacFie - were inventors and entrepreneurs, and it was also supported by radical laissez-faire economists (The Economist
 published anti-patent views), law scholars, scientists (who were 
concerned that patents were obstructing research) and manufacturers.  Johns summarizes some of their main arguments as follows:
- [Patents] projected an artificial idol of the single inventor, radically denigrated the role of the intellectual commons, and blocked a path to this commons for other citizens — citizens who were all, on this account, potential inventors too. [...] Patentees were the equivalent of squatters on public land — or better, of uncouth market traders who planted their barrows in the middle of the highway and barred the way of the people.
 
Similar debates took place during that time in other European countries such as France, Prussia, Switzerland and the Netherlands (but not in the USA).
Based on the criticism of patents as state-granted monopolies inconsistent with free trade, the Netherlands abolished patents in 1869 (having established them in 1817), and did not reintroduce them until 1912. In Switzerland, criticism of patents delayed the introduction of patent laws until 1907.
Contemporary arguments
Contemporary
 arguments have focused on ways that patents can slow innovation by: 
blocking researchers' and companies' access to basic, enabling 
technology, and particularly following the explosion of patent filings 
in the 1990s, through the creation of "patent thickets"; wasting 
productive time and resources fending off enforcement of low-quality 
patents that should not have existed, particularly by "patent trolls"; 
and wasting money on patent litigation.  Patents on pharmaceuticals have
 been a particular focus of criticism, as the high prices they enable 
puts life-saving drugs out of reach of many people.
Blocking innovation
The
 most general argument against patents is that "intellectual property" 
in all its forms represents an effort to claim something that should not
 be owned, and harms society by slowing innovation and wasting 
resources.
Law professors Michael Heller and Rebecca Sue Eisenberg have described an ongoing tragedy of the anticommons with regard to the proliferation of patents in the field of biotechnology,
 wherein  intellectual property rights have become so fragmented that, 
effectively, no one can take advantage of them as to do so would require
 an agreement between the owners of all of the fragments.
Some public campaigns for improving access to medicines and genetically modified food
 have expressed a concern for "preventing the over-reach" of 
intellectual property protection including patent protection, and "to 
retain a public balance in property rights".  Some economists and scientists and law professors
  have raised concerns that patents retard technical progress and 
innovation.  Others claim that patents have had no effect on research, 
based on surveys of scientists.
Poor patent quality and patent trolls
Patents
 have also been criticized for being granted on already-known 
inventions, with some complaining in the United States that the USPTO 
fails "to do a serious job of examining patents, thus allowing bad 
patents to slip through the system." On the other hand, some argue that because of low number of patents going into litigation, increasing quality of patents at patent prosecution
 stage increases overall legal costs associated with patents, and that 
current USPTO policy is a reasonable compromise between full trial on 
examination stage on one hand, and pure registration without 
examination, on the other hand.
Enforcement of patents – especially patents perceived as being overly broad – by patent trolls, has brought criticism of the patent system,
 though some commentators suggest that patent trolls are not bad for the
 patent system at all but instead realign market participant incentives,
 make patents more liquid, and clear the patent market.
Some patents granted in Russia have been denounced as pseudoscientific (for example, health-related patents using lunar phase or religious icons).
Litigation costs
According to James Bessen,
 the costs of patent litigation exceed their investment value in all 
industries except chemistry and pharmaceuticals. For example, in the 
software industry, litigation costs are twice the investment value.
  Bessen and Meurer also note that software and business model 
litigation accounts for a disproportionate share (almost 40 percent) of 
patent litigation cost, and the poor performance of the patent system 
negatively affects these industries.
Different industries but one law
Richard Posner
 noted that the most controversial feature of US patent law is that it 
covers all industries in the same way, but not all industries benefit 
from the time-limited monopoly a patent provides in order to spur 
innovation.
  He said that while the pharmaceutical industry is "poster child" for 
the need for a twenty-year monopoly, since costs to bring to a market 
are high, the time of development is often long, and the risks are high,
 in other industries like software the cost and risk of innovation is 
much lower and the cycle of innovation is quicker, and obtaining and 
enforcing patents and defending against patent litigation is generally a
 waste of resources in those industries.
Pharmaceutical patents
Some
 have raised ethical objections specifically with respect to 
pharmaceutical patents and the high prices for medication that they 
enable their proprietors to charge, which poor people in the developed 
world, and developing world, cannot afford.
 Critics also question the rationale that exclusive patent rights and 
the resulting high prices are required for pharmaceutical companies to 
recoup the large investments needed for research and development.
 One study concluded that marketing expenditures for new drugs often 
doubled the amount that was allocated for research and development.
In 2003, World Trade Organization (WTO) reached an agreement, which provides a developing country with options for obtaining needed medications under compulsory licensing or importation of cheaper versions of the drugs, even before patent expiration.
In 2007 the government of Brazil declared Merck's efavirenz
 anti-retroviral drug a "public interest" medicine, and challenged Merck
 to negotiate lower prices with the government or have Brazil strip the 
patent by issuing a compulsory license.
It is reported that Ghana, Tanzania, the Democratic Republic of Congo and Ethiopia have similar plans to produce generic antiviral drugs. Western
 pharmaceutical companies initially responded with legal challenges, but
 some have now promised to introduce alternative pricing structures for 
developing countries and NGOs.
In July 2008 Nobel Prize-winning scientist Sir John Sulston called for an international biomedical treaty to clear up issues over patents.
In response to these criticisms, one review concluded that less than 5 percent of medicines on the World Health Organization's list of essential drugs are under patent.
 Also, the pharmaceutical industry has contributed US$2 billion for 
healthcare in developing countries, providing HIV/AIDS drugs at lower 
cost or even free of charge in certain countries, and has used 
differential pricing and parallel imports to provide medication to the 
poor.
 Other groups are investigating how social inclusion and equitable 
distribution of research and development findings can be obtained within
 the existing intellectual property framework, although these efforts 
have received less exposure.
Quoting a World Health Organization
 report, Trevor Jones (director of research and development at the 
Wellcome Foundation, as of 2006) argued in 2006 that patent monopolies 
do not create monopoly pricing.
 He argued that the companies given monopolies "set prices largely on 
the willingness/ability to pay, also taking into account the country, 
disease and regulation" instead of receiving competition from legalized 
generics.
Proposed alternatives to the patent system
Alternatives
 have been discussed to address the issue of financial incentivization 
to replace patents. Mostly, they are related to some form of direct or 
indirect government funding. One example is Joseph Stiglitz's idea of providing "prize money"
 (from a "prize fund" sponsored by the government) as a substitute for 
the lost profits associated with abstaining from the monopoly given by a
 patent.
 Another approach is to remove the issue of financing development from 
the private sphere altogether, and to cover the costs with direct 
government funding.