How we cite our quotes: Section.Part (if applicable).Paragraph
Quote #10
Thus, two men pull the oars of a boat by common convention for common interest, without any promise or contract; thus gold and silver are made the measures of exchange; thus speech and words and language are fixed by human convention and agreement. Whatever is advantageous to two or more persons, if all perform their part; but what loses all advantage if only one perform, can arise from no other principle. (AIII.8)
Through the simple example of two guys rowing a boat, we get an idea of how useful cooperation can be. Throughout Enquiry, Hume emphasizes that it's natural for people to organize themselves into groups and societies: it's all about people working together to achieve something, and this has led to common languages and currencies. Pretty straightforward, no?