The early case of W & A McArthur Ltd v Queensland,[3] declared: "Trade and commerce" between different countries—we leave out for the present the word "intercourse"—has never been confined to the mere act of transportation of merchandise over the frontier.
All the commercial arrangements of which transportation is the direct and necessary result form part of "trade and commerce."
The mutual communings, the negotiations, verbal and by correspondence, the bargain, the transport and the delivery are all, but not exclusively, parts of that class of relations between mankind which the world calls "trade and commerce.
to make laws with respect to trade and commerce with other countries and among the States may well be considered artificial and unsuitable to modern times.
92 lays down a general rule of economic freedom, and necessarily binds all parties and authorities within the Commonwealth, including the Commonwealth itself, because, as was pointed out by the Privy Council itself, it establishes a "system based on the absolute freedom of trade among the States" (Colonial Sugar Refining Co v Irving[15]).