Patent law only protects “inventions” as defined under the Patent Act. The scope of the word “invention” is limited to those categories set out in the Act, and is further proscribed by provisions proclaiming what cannot be patented. Note that even if an invention falls within the definition of the Act, it must meet the prerequisites of Novelty (Anticipation), Utility, and non-obviousness (inventiveness) to qualify for patent protection.

Section 2 of the Patent Act defines “invention” as the following:¹

any new and useful art, process, machine, manufacture or composition of matter, or any new and useful improvement in any art, process, machine, manufacture or composition of matter

In addition, subsection 27(8) of the Act states that:

No patent shall be granted for any mere scientific principle or abstract theorem.

See also: claim construction.

In determining whether something is patentable subject matter, it is paramount to construe the claims of the patent (or patent application) in a purposive manner to determine whether the “subject matter defined by the claims” are patentable, and not merely what the inventor claims to have invented.² The “inventive concept” should not be the sole basis for determination of patentable subject matter.³

As provided for in section 2, there are five general categories of patentable inventions. However, the terms “art, process, machine, manufacture or composition of matter” are not specifically defined in the Act and has therefore been subject to judicial scrutiny.

The word “art” is a broad term, and is meant to encompass application of new knowledge to effect a desired result. In Shell Oil Co v Commissioner of Patents,⁴ the Supreme Court held that a new use for an old compound was patentable. Wilson J., for the Court, wrote:

I believe it is the application of this new knowledge to effect a desired result which has an undisputed commercial value and that it falls within the words “any new and useful art”. I think the word “art” in the context of the definition must be given its general connotation of “learning” or “knowledge” as commonly used in expressions such as “the state of the art” or “the prior art”. The appellant’s discovery in this case has added to the cumulative wisdom on the subject of these compounds by a recognition of their hitherto unrecognized properties and it has established the method whereby these properties may be realized through practical application. In my view, this constitutes a “new and useful art” and the compositions are the practical embodiment of the new knowledge.⁵

The term “art” in fact appears to encompass both “method” and “process”,⁶ but is not confined only to new processes.⁷ “Art” includes any new and inventive method of applying knowledge (not necessarily scientific knowledge).

The elements required for something to be an “art” are threefold:

1. it must not be a disembodied idea but have a method of practical application;
2. it must be a new and inventive method of applying skill and knowledge; and
3. it must have a commercially useful result.⁸

Under this test, “business methods” may be patentable subject matter.⁹

The word “process” has generally been held to be synonymous with the word “method” (although the word “method” is not itself used in the definition of “invention” in the Patent Act).¹⁰ The Supreme Court in Commissioner of Patents v Ciba Ltd gave some observations on the word “process” in holding that an old method used on known materials to produce a new and useful result is patentable:

A process implies the application of a method to a material or materials. The method may be known and the materials may be known, but the idea of making the application of the one to the other to produce a new and useful compound may be new […].¹¹

Fox on Patents¹² provides the following definition:

A “process” may be defined as a mode, method or operation, by which a result or effect is produced by chemical action, by the operation or application of some element or power of nature, or of one substance to another. Shortly stated a process is the use of a method or the performance of an operation to produce a result. A process must consist of two elements, namely, a method or a procedure and the material or materials to which it is applied.¹³ The use of the method must produce a useful result to meet the utility requirement of patentability.

A “machine” is “the embodiment in mechanism of any function or mode of operation designed to accomplish a particular effect”. This encompasses many forms of mechanical devices that perform some function and produce a new result.¹⁴

“Manufacture” is a term that connotes the “making” of something.¹⁵ The word, as used in the original Statute of Monopolies in the UK, has been interpreted by English courts as meaning “something made by the hands of man”.¹⁶ However, this broad meaning does not necessarily include manufacture of living species. As the majority of the Supreme Court held in Harvard College v Commissioner of Patents, “manufacture” is understood to denote a non-living mechanistic product or process.¹⁷

“Composition of matter” includes all composite matter, such as a chemical compound or a mechanical mixture.¹⁸ Chemicals, for example, can be protected per se without being limited to a single purpose.¹⁹ However, “composition of matter” (although broader than “manufacture”) does not include “higher life forms” such as mammals.²⁰

Any new and useful “improvements” on an art, process, machine, manufacture or composition of matter is also patentable. It is almost certainly true that most inventions are improvements of some kind on existing inventions. Thus, the patentability of improvements should not be surprising. The Patent Act, in addition to defining “invention” to include “improvements”, also explicitly mentions improvements under s. 32:

32. Any person who has invented any improvement on any patented invention may obtain a patent for the improvement, but he does not thereby obtain the right of making, vending or using the original invention, nor does the patent for the original invention confer the right of making, vending or using the patented improvement.²¹

Therefore, although a patent may be obtained for an improvement to an existing invention, if the underlying invention is patented by someone other than the inventor of the improvement, the new owner must obtain or licence the patent rights from the owner of the existing patent to practice the invention.²² This is consistent with the view of a patent as conferring an exclusionary right rather than a positive right.

Improvements need not be a physical change to an existing invention. For example, new uses for old compounds are improvements (provided they are also new, useful, and non-obvious).²³ Other “improvements” include combination of old elements to achieve a new result,²⁴ or the substitution of materials.²⁵ Elimination of parts may also be a patentable improvement.²⁶

The Patent Act prohibits patent protection for mere scientific principles or abstract theorems. This echoes the broad policy considerations in intellectual property law to prevent monopolization of mere ideas, which belong in the public domain.²⁷ Patents are only granted to applications of ideas or principles in a new and useful way, not for “speculation”.²⁸ However, whether something is a mere principle/theorem versus the application thereof may be difficult to distinguish in practice.

For example, mere ideas and schemes are unpatentable.²⁹ As are purported inventions that involve merely a series of mental steps or algorithms that can be worked out in the mind alone.³⁰ Something with “practical application” could be patentable subject matter, and not merely a discovery of a scientific principle, so long as “the patent claims are for a practical solution to a practical problem”.³¹ Where a claim or set of claims is so broad so as to claim all possible means for solving a problem, those claims are invalid since it would be tantamount to claiming all applications of the principle, and therefore, the principle itself.³²