 There are three varieties of these ambiguities and amphibolies: (1) When either the expression or the name has strictly more than one meaning… (2) when by custom we use them so; (3) when words that have a simple sense taken alone have more than one meaning in combination; e.g. ‘knowing letters’. For each word, both ‘knowing’ and ‘letters’, possibly has a single meaning: but both together have more than one-either that the letters themselves have knowledge or that someone else has it of them. (Sophistical Refutations bk. 4)