Foolish behavior is opposed to temperate behavior. [Premise—cf. 332b]
Foolish behavior is a result of folly. [Premise—cf. 332b]
Temperate behavior is a result of temperance. [Premise—cf. 332b]
If x and y are opposing types of behavior, they are the result of opposing types of character traits. [Premise—cf. 332c]
So folly is opposed to temperance. [2, 3, 4, 5]
Anything that stands in a relation of opposition has exactly one opposite. [Premise—cf. 332d]
Hence, wisdom = temperance. [1, 6, 7—cf. 333b]
Against the Possibility of Incontinence (akrasia—weakness of will)
x is bad iff x’s net result is greater pain than pleasure. [Premise—cf. 354d]
Suppose that the following is possible: S knows that x is bad, but does x anyway, having been overcome by the pleasure that attends x. [Premise—for the purpose ofreductio ad absurdum]
On this hypothesis, S knows that x’s net result is greater pain than pleasure, but S does x anyway, having been overcome by the pleasure that attends x. [1, 2]
An individual can be overcome by pleasure only if pleasure outweighs pain; that is, if there is more pleasure than pain. [Premise—cf. 355d ff.]
But then it’s impossible that S should be overcome by the pleasure that attends x when x is, by hypothesis, bad. [3, 4]
Therefore, the supposition in (2) is impossible. [5]