第4章

There are two styles of refutation: for some depend on the language used, while some are independent of language.Those ways of producing the false appearance of an argument which depend on language are six in number: they are ambiguity, amphiboly, combination, division of words, accent, form of expression.Of this we may assure ourselves both by induction, and by syllogistic proof based on this-and it may be on other assumptions as well-that this is the number of ways in which we might fall to mean the same thing by the same names or expressions.Arguments such as the following depend upon ambiguity.'Those learn who know: for it is those who know their letters who learn the letters dictated to them'.For to 'learn' is ambiguous; it signifies both 'to understand' by the use of knowledge, and also 'to acquire knowledge'.Again, 'Evils are good:

for what needs to be is good, and evils must needs be'.For 'what needs to be' has a double meaning: it means what is inevitable, as often is the case with evils, too (for evil of some kind is inevitable), while on the other hand we say of good things as well that they 'need to be'.Moreover, 'The same man is both seated and standing and he is both sick and in health: for it is he who stood up who is standing, and he who is recovering who is in health: but it is the seated man who stood up, and the sick man who was recovering'.For 'The sick man does so and so', or 'has so and so done to him' is not single in meaning: sometimes it means 'the man who is sick or is seated now', sometimes 'the man who was sick formerly'.

Of course, the man who was recovering was the sick man, who really was sick at the time: but the man who is in health is not sick at the same time: he is 'the sick man' in the sense not that he is sick now, but that he was sick formerly.Examples such as the following depend upon amphiboly: 'I wish that you the enemy may capture'.Also the thesis, 'There must be knowledge of what one knows': for it is possible by this phrase to mean that knowledge belongs to both the knower and the known.Also, 'There must be sight of what one sees: one sees the pillar: ergo the pillar has sight'.Also, 'What you profess to-be, that you profess to-be: you profess a stone to-be: ergo you profess-to-be a stone'.Also, 'Speaking of the silent is possible':

for 'speaking of the silent' also has a double meaning: it may mean that the speaker is silent or that the things of which he speaks are so.There are three varieties of these ambiguities and amphibolies:

(1) When either the expression or the name has strictly more than one meaning, e.g.aetos and the 'dog'; (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.