BOOK I. VII. 20-30
to the unthinking to be disconcerted, if they do not see what follows in consequence. Why is it necessary? In order that in this matter we may not behave unsuitably, nor at haphazard, nor confusedly.
And the same holds true of hypotheses and hypothetical arguments. For it is necessary at times to postulate some hypothesis as a sort of stepping-stone for the subsequent argument. Are we, therefore, to grant any and every hypothesis that is proposed, or not every one? And if not every one, what one? And when a man has granted an hypothesis, must he abide for ever by it and maintain it, or are there times when he should abandon it and accept only the consequences which follow from it without accepting those which are opposed to it?25—Yes.—But someone says, "If you once admit an hypothesis that involves a possibility, I will compel you to be drawn on to an impossibility." Shall the prudent man refuse to engage with this person, and avoid enquiry and discussion with him? Yet who but the prudent is capable of using argument and skilful in question and answer, and, by Zeus, proof against deceit and sophistic fallacies? But shall he argue, indeed, and then not take pains to avoid conducting himself recklessly and at haphazard in argument? And if he does not, how will he any longer be the sort of man we think he is? But without some such exercise and preparation in formal reasoning, how will he be able to maintain the continuity of the argument? Let them show that he will be able, and all these speculations become mere superfluity; they were absurd and inconsistent with our preconception of the good man.
30Why are we still indolent and easy-going and
