Otherwise there will be nothing by which we can prove anything; there must be something which either is or is believed to be true, by means of which doubtful things may be rendered credible. We may regard as certainties, first, those things which we perceive by the senses, things for instance that we hear or see, such as signs or indications; secondly, those things about which there is general agreement, such as the existence of the gods or the duty of loving one's parents;

thirdly, those things which are established by law or have passed into current usage, if not throughout the whole world, at any rate in the nation or state where the case is being pleaded—there are for instance many rights which rest not on law, but on custom; finally, there are the things which are admitted by either party, and whatever has already been proved or is not disputed by our adversary.

Thus for instance it may be argued that since the world is governed by providence, the state should similarly be governed by some controlling power: it follows that the state must be so governed, once it is clear that the world is governed by providence.

Further, the man who is to handle arguments correctly must know the nature and meaning of everything and their usual effects. For it is thus that we arrive at probable arguments or εἰκότα as the Greeks call them.

With regard to credibility there are three degrees. First, the highest, based on what usually happens, as for instance the assumption that children are loved by their parents. Secondly, there is the highly probable, as for instance the assumption that a man in the enjoyment of good health will probably live till to-morrow. The third degree is found where there is nothing absolutely against an assumption, such as that a theft committed in a house was the work of one of the household.

Consequently Aristotle in the second book of his Rhetoric has made a careful examination of all that commonly happens to things and persons, and what things and persons are naturally adverse or friendly to other things or persons, as for instance, what is the natural result of wealth or ambition or superstition, what meets with the approval of good men, what is the object of a soldier's or a farmer's desires, and by what means everything is sought or shunned.

For my part I do not propose to pursue this subject. It is not merely a long, but an impossible or rather an infinite task; moreover it is within the compass of the common understanding of mankind. If, however, anyone wishes to pursue the subject, I have indicated where he may apply.

But all credibility, and it is with credibility that the great majority of arguments are concerned, turns on questions such as the following: whether it is credible that a father has been killed by his son, or that a father has committed incest with his daughter, or to take questions of an opposite character, whether it is credible that a stepmother has poisoned her stepchild, or that a man of luxurious life has committed adultery; or again whether a crime has been openly committed, or false evidence given for a small bribe, since each of these crimes is the result of a special cast of character as a rule, though not always; if it were always so, there would be no room for doubt, and no argument.

Let us now turn to consider the places of arguments, although some hold that they are identical with the topics which I have already discussed above. In previous chapter. But I do not use this term in its usual acceptance, namely, commonplaces See ii. iv. 22, v. xii. 6 and xiii. 57. directed against luxury, adultery, and the like, but in the sense of the secret places where arguments reside, and from which they must be drawn forth.

For just as all kinds of produce are not provided by every country, and as you will not succeed in finding a particular bird or beast, if you are ignorant of the localities where it has its usual haunts or birthplace, as even the various kinds of fish flourish in different surroundings, some preferring a smooth and others a rocky bottom, and are found on different shores and in divers regions (you will for instance never catch a sturgeon or wrasse in Italian waters), so not every kind of argument can be derived from every circumstance, and consequently our search requires discrimination.

Otherwise we shall fall into serious error, and after wasting our labour through lack of method we shall fail to discover the argument which we desire, unless assisted by some happy chance. But if we know the circumstances which give rise to each kind of argument, we shall easily see, when we come to a particular place, what arguments it contains.

Firstly, then, arguments may be drawn from persons; for, as I have already said, v. viii. 4. all arguments fall into two classes, those concerned with things and those concerned with persons, since causes, time, place, occasion, instruments, means and the like are all accidents of things. I have no intention of tracing all the accidents of persons, as many have done, but shall confine myself to those from which arguments may be drawn.

Such are birth, for persons are generally regarded as having some resemblance to their parents and ancestors, a resemblance which sometimes leads to their living disgracefully or honourably, as the case may be; then there is nationality, for races have their own character, and the same action is not probable in the case of a barbarian, a Roman and a Greek;

country is another, for there is a like diversity in the laws, institutions and opinions of different states; sex, since for example a man is more likely to commit a robbery, a woman to poison; age, since different actions suit different ages; education and training, since it makes a great difference who were the instructors and what the method of instruction in each individual case;

bodily constitution, for beauty is often introduced as an argument for lust, strength as an argument for insolence, and their opposites for opposite conduct; fortune, since the same acts are not to be expected from rich and poor, or from one who is surrounded by troops of relations, friends or clients and one who lacks all these advantages; condition, too, is important, for it makes a great difference whether a man be famous or obscure, a magistrate or a private individual, a father or a son, a citizen or a foreigner, a free man or a slave, married or unmarried, a father or childless.

Nor must we pass by natural disposition, for avarice, anger, pity, cruelty, severity and the like may often be adduced to prove the credibility or the reverse of a given act; it is for instance often asked whether a man's way of living be luxurious, frugal or parsimonious. Then there is occupation, since a rustic, a lawyer, a man of business, a soldier, a sailor, a doctor all perform very different actions.

We must also consider the personal ambitions of individuals, for instance whether they wish to be thought rich or eloquent, just or powerful. Past life and previous utterances are also a subject for investigation, since we are in the habit of inferring the present from the past. To these some add passion, by which they mean some temporary emotion such as anger or fear; they also add design, which may refer to the past,