this manner allows others who may make or use similar inventions to know whether they are infringing the patent. They also allow others to design around the claims (change and, ideally, improve upon the invention) without infringing the patent.
Based on utilitarian rather than natural-right theory, patents were among the legal concepts introduced to the American colonies by British settlers. Some colonies began to issue patents as early as 1641 and some states continued to do so through the period of the Articles of Confederation. To resolve their growing conflict over patents, the Constitutional Convention of 1789 resolved to create a national system through the Constitution itself, whose Article I, Section 8 authorized Congress to reward exclusive rights for a limited time to authors and inventors “for their respective writings and discoveries.” As secretary of state, Thomas Jefferson was responsible for implementing the first Patent Act (1790), although a pro forma registration system was quickly substituted (in 1793) for the original government approval process. Formal examination of applications by professional examiners was introduced by the 1836 revision of the Patent Act. Additional hurdles (for example, what later became known as the “non-obviousness” criterion) were introduced by the courts in the mid- and late-19th century. The contemporary patent system largely reflects the last major revision of the patent statute, the Patent Act of 1952, although some important changes affecting patent term and publication of pre-grant patent applications have been introduced in the last decade.
The statutory provision on patent-eligible subject matter is brief and has changed little from the version written by Thomas Jefferson: “any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof.”
The effective scope of patenting has been determined primarily by court cases, among them decisions upholding patents on genetically altered living organisms, isolated genes and parts of genes, computer software, and methods of performing business functions. There are no statutory exclusions, although as a result of legislation enacted in 1996 subsequent patents on surgical procedures may not be enforced against individual physicians and as a result of legislation enacted in 1999, accused infringers of business method patents can assert a prior use defense. It has been declared USPTO policy not to issue patents on human beings; this was recently codified in statute. And it remains axiomatic that principles, laws of nature, mental processes, intellectual concepts, ideas, natural phenomena, and mathematical formulae are not patentable, although the line