As everyone knows, contracts of insurance are often called “insurance policies.” On and off, over many years, I have wondered why, but have been too lazy to try and find out.  This project has given me what I tentatively think may be the answer.  It’s definitional. In Volume II of Samuel Johnson’s A DICTIONARY OF THE ENGLISH LANGUAGE at p. 1477, there is a definition of “policy,” and it contains three alternatives. Only one of them is possibly applicable. Definition #2 reads this way: “Art, prudence; management of affairs; stratagem.” [Spelling Updated]  Surely having insurance is a prudent management of one’s affairs, so–perhaps–the contract which constituted exactly that ended up being called a “policy.”  In these days and times, it is relatively common to use a noun into a very, for some purposes. Long ago we might see verbs being converted into closely related nouns.