What is the legal test for carrying on a business?

In law, the meaning of "carrying on a business" may differ depending on the context in which it is used. Provincial partnership acts typically define "business" as including "every trade, occupation and profession". The kinds of factors that may be relevant to determining whether there is a business are contained in the existing legal definitions. One simple definition of "carrying on trade or business" is given in Black's Law Dictionary (6th ed. 1990), at p. 214: "To hold one's self out to others as engaged in the selling of goods or services." Another definition requires at least three elements to be present: (1) the occupation of time, attention and labour; (2) the incurring of liabilities to other persons; and (3) the purpose of a livelihood or profit: see Gordon v. The Queen, 1961 CanLII 13 (SCC), [1961] S.C.R. 592, per Cartwright J., dissenting but not on this point, at p. 603.