Seldom does a Patent Office policy manual get trimmed, but this is what the Canadian Patent Office laudably did earlier this year to a section of the Manual of Patent Office Practice related to so-called "spirit and scope" statements. Directed by this section, Canadian examiners had routinely objected to language like the "spirit of the invention" in the description of patent applications, which allegedly broadened the scope of the patent claims.

However, any fear about the "spirit" of the invention was apparently considered to be unfounded, and this may explain the unceremonious withdrawal of the above-mentioned section. The Supreme Court of Canada explained in Free World Trust v Électro Santé 2000 SCC 66 that, while the Patent Act promotes adherence to the claim language, this language has to be interpreted in an informed and purposive way. There is no recourse to such vague notions as the "spirit of the invention" to expand it further.

The informed and purposive interpretation of the claims is, of course, carried out with regard to both the patent specification and the common general knowledge of the skilled person, as of the date of the publication of the patent.

Consistent with what the Supreme Court said in Free World Trust, the same Court in Sanofi v Apotex, 2008 SCC 61, explicitly clarified that even in cases where reference to the description — which may include the "spirit of the invention" — is acceptable to determine the inventive concepts of the claims, it is not permissible to read the specification in order to construe the claims more narrowly or widely than the text will allow.

The withdrawal of objections to "spirit and scope" statements in the description is therefore a first encouraging step by the Canadian Patent Office to rid itself of at least one "spirit" which has haunted it and its office manual. This should enable examiners to better focus on a scope of patent protection which is — as the Supreme Court expressed and demanded — not only fair, but reasonably predictable.

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