2 Aristotle 3 · On Arguing. Handed down at the Lyceum, from his Sophistical Refutations and his Ethics
This book does not set out the forms of inference, nor where starting points come from. Those belong in a school, not in a life. What is kept is the three things a person needs among other people: how to see whether you are after the truth or after the win, how to hear a bad argument, and how far a thing needs proving before you stop.
3.1Some bring the surveyor’s rule to human affairs, find it will not measure them, and conclude that human affairs admit of no reasoning.
3.2They have gone wrong at both ends.
3.3It is the mark of an educated man to look, in each kind of thing, for only as much exactness as that kind allows.
3.4The carpenter and the geometer both use a right angle.
3.5The geometer wants to know what a right angle is. The carpenter wants one good enough to build the house.
3.6If you fault the carpenter for not knowing geometry, you are not being rigorous. You do not understand carpentry.
3.7And if you bring the carpenter’s roughness to geometry, you are not being easygoing. You will not get geometry done.
3.8So ask first: how exact can this kind of thing be made?
3.9About the motions of the stars, very exact.
3.10About whether a man should say that sentence now, not nearly so exact.
3.11Not exact does not mean there is no better and worse.
3.12Two carpenters both work without geometry, and one man’s house falls down and the other man’s does not.
3.13In human affairs it is exactly that better and worse we are after: not being right to the last part, but being wrong fewer times than yesterday.
3.14Someone objects: then in human affairs does not everyone simply say what he likes?
3.15No. Because one thing still governs: he who can give the reason beats him who cannot.
3.16You cannot prove all the way down, and you must still prove as far as this kind of thing goes.
3.17Stopping where you should stop is not laziness. Going past where you should stop is not diligence.