ON THE USE OF VARIABLE PREMISSES AND HYPOTHETICAL ARGUMENTS AND THE LIKE 1-8
Most men ignore the fact that the treatment of variable premisses and hypothetical arguments and again of syllogisms that conclude by way of question, and, in a word, of all such arguments is concerned with conduct. For really, whatever subject we are dealing with, our aim is to find how the good man may fitly deal with it and fitly behave towards it. It follows then that either they must say that the virtuous man will not condescend to question and answer, or that if he does he will take no care to avoid behaving lightly and at random in questioning and answering; or else, if they accept neither alternative, they must admit that we have to investigate those subjects round which question and answer chiefly turn. For what do we promise in a discussion? To establish what is true, to remove what is false, to withhold a**ent in what is uncertain. Is it enough then merely to learn that this is so?
'It is enough.'
Is it enough then for him who wishes not to go wrong in the use of coin merely to be told why you accept genuine drachmas and reject spurious ones?
'It is not enough.'
What then must you acquire besides? Surely you must have a faculty to test and distinguish genuine drachmas from spurious. Is it not true . then in regard to argument also that merely to hear what is said is not enough; a man must acquire the faculty to test and distinguish the true from the false and the uncertain?
'It must be so.'
This being so, what is required in argument?
'Accept what follows from the premisses you have duly granted.'
Here again, is it enough merely to know this? No, you must learn how a conclusion follows from the premisses, and how sometimes one proposition follows from one other, and sometimes from many together.
May we say then that this faculty too must be acquired by him who is to behave with good sense in discussion, and who is himself to prove each point in his demonstration and to follow the demonstrations of others, and to avoid being led astray by sophistical arguments, posing as demonstrations? Thus it comes about that we are led to think it really necessary to discuss and to practise the arguments and moods which are conclusive.
But note this: there are cases where we have granted the premisses properly, and such and such a conclusion follows which, though it follows, is none the less false. What then is it fitting for me to do? Must I accept the false conclusion? How can I do that? Must I say I was wrong in granting the premisses?
'No, you may not do this either.'
That it does not follow from the premisses granted?
'No, you may not do this.'
What then is one to do in these circumstances? May we not say that just as in order to be in debt it is not enough merely to borrow, but one must remain a borrower and not have paid off the loan, so in order to be bound to admit an inference it is not enough to have granted the premisses, but one must abide by having granted them?
In a word, if they remain to the end as we granted them, we are absolutely bound to remain by our concessions and accept what follows the premisses; if, on the other hand, they do not remain as they were granted, we are also absolutely bound to abandon the concession and no longer to accept what is inconsistent with the premisses; for since we have abandoned our agreement as to the premisses, this inference which is drawn no longer concerns us or touches us. We must then examine into premisses of this sort and into such changes and alterations in them, by which they are changed in the actual process of question or answer or syllogism or the like, and so afford occasion to the foolish to be troubled because they do not see the sequence of the argument. Why must we do so? That in this sphere we may do what is fitting by avoiding what is random or confused in argument.
And we ought to do the same with hypotheses and hypothetical arguments. For it is necessary sometimes to a**ume a hypothesis as a step to the next argument. Must we then concede every given hypothesis or not? And if not every one, which? And, having conceded it, must we abide by it once for all and maintain it, or are we sometimes to abandon it, and are we to accept what follows from it and reject what conflicts with it?
'Yes.'
But a man says, 'If you accept a hypothesis of what is possible, I will reduce you in argument to what is impossible.'
Will the prudent man refuse to meet him in argument, and avoid examination and discussion with him? Nay, it is just the prudent man who is capable of reasoning logically and who is expert at questioning and answering, yes and who is proof against deception and sophistry. Will he then consent to argue, but take no pains to avoid being careless and casual in argument? If so, will he not cease to be the man we consider him to be? But without some such training and preparation as I suggest can he guard the sequence of his argument? Let them show that he can, and then all these speculations are idle; they were absurd and inconsistent with the conception we have formed of the good man.
Why do we persist in being lazy and indolent and sluggish, why do we seek excuses to enable us to avoid toiling early and late to perfect ourselves in logical theory?
'Do you call it parricide if I go wrong in logic?'
Slave, here is no father for you to k**. You ask what you have done, you have committed the one error which was possible in this field. Your answer is the very one I made myself to Rufus when he rebuked me because I could not find the one missing step in a syllogism. 'Well,' said I, 'I suppose I have not burnt the Capitol down'; and he answered, 'Slave, the missing step here is the Capitol.'
You are not going to tell me, are you, that setting fire to the Capitol and k**ing one's father are the only forms of wrongdoing? To deal with one's impressions without thought or method, to fail to follow argument or demonstration or sophism, in a word, to be unable to see what concerns himself and what does not in question and answer—is there no wrongdoing, I ask, in any of these?