LESSON 5

The Method to Be Followed in the Search for Truth

Chapter 3: 994b 32-995a 20

             171. The way in which people are affected by what they hear depends upon the things to which they are accustomed; for it is in terms of such things that we judge statements to be true, and anything over and above these does not seem similar but less intelligible and more remote. For it is the things to which we are accustomed that are better known.

             172. The great force which custom has is shown by the laws, in which legendary and childish elements prevail over our knowledge of them, because of custom.

             173. Now some men will not accept what a speaker says unless he speaks in mathematical terms; and others, unless he gives examples; while others expect him to quote a poet as an authority. Again, some want everything stated with certitude, while others find certitude annoying, either because they are incapable of comprehending anything, or because they consider exact inquiry to be quibbling; for there is some similarity. Hence it seems to some men that, just as liberality is lacking in the matter of a fee for a banquet, so also is it lacking in arguments.

             174. For this reason one must be trained how to meet every kind of argument; and it is absurd to search simultaneously for knowledge and for the method of acquiring it; for neither of these is easily attained.

             175. But the exactness of mathematics is not to be expected in all cases, but only in those which have no matter. This is why its method is not that of natural philosophy; for perhaps the whole of nature contains matter. Hence we must first investigate what nature is; for in this way it will become evident what the things are with which natural philosophy deals, and whether it belongs to one science or to several to consider the causes and principles of things.

COMMENTARY

             331. Having shown that the study of truth is in one sense difficult and in another easy, and that it belongs preeminently to first philosophy, the Philosopher now exposes the proper method of investigating the truth. In regard to this he does two things. First (171:C 331), he gives the different methods which men follow in the study of truth. Second (174:C 335), he shows which method is the proper one ("For this reason one must").

             In regard to the first he does two things. First, he shows how powerful custom is in the study of truth. Second (173:C 334), he concludes that the different methods which men employ in the study of truth depend on the different things to which they are accustomed ("Now some men").

             In regard to the first he does two things. First, he shows how powerful custom is in the study of truth. Second (172:C 333), he makes this clear by an example ("The great force").

             He says, first, that the way in which people are affected by what they hear depends upon the things to which they are accustomed, because such things are more willingly heard and more easily understood. For things spoken of in a manner to which we are accustomed seem to us to be acceptable; and if any things are said to us over and above what we have been accustomed to hear, these do not seem to have the same degree of truth. As a matter of fact they seem less intelligible to us and further removed from reason just because we are not accustomed to them; for it is the things which we are accustomed to hear that we know best of all.

             332. Now the reason for this is that things which are customary become natural. Hence a habit, which disposes us in a way similar to nature, is also acquired by customary activity. And from the fact that someone has some special sort of nature or special kind of habit, he has a definite relationship to one thing or another. But in every kind of cognition there must be a definite relationship between the knower and the object of cognition. Therefore, to the extent that natures and habits differ, there are diverse kinds of cognition. For we see that there are innate first principles in men because of their human nature, and that what is proper to some special virtue appears good to one who has this habit of virtue; and, again, that something appears palatable to the sense of taste because of its disposition. Therefore, since custom produces a habit which is similar to nature, it follows that what is customary is better known.

             333. The great force (172).

             Here he makes his previous statement clear by giving a concrete case. He says that the laws which men pass are positive evidence of the force of custom; for the legendary and childish elements in these laws are more effective in winning assent than is knowledge of the truth. Now the Philosopher is speaking here of the laws devised by men, which have as their ultimate end the preservation of the political community. Therefore the men who have established these laws have handed down in them, in keeping with the diversity of peoples and nations involved, certain directives by which human souls might be drawn away from evil and persuaded to do good, although many of them, which men had heard from childhood and of which they approved more readily than of what they knew to be true, were empty and foolish. But the law given by God directs men to that true happiness to which everything false is opposed. Therefore there is nothing false in the divine law.

             334. Now some men (173).

             Here he shows how men as a result of custom use different methods in the study of truth. He says that some men listen to what is said to them only if it is mathematical in character; and this is acceptable to those who have been educated in mathematics because of the habits which they have. Now since custom is like nature, the same thing can also happen to certain men because they are poorly disposed in some respect, e.g., those who have a strong imagination but little intelligence. Then there are others who do not wish to accept anything unless they are given a concrete example, either because they are accustomed to this or because their sensory powers dominate and their intellect is weak. Again, there are some who think that nothing is convincing enough unless a poet or some authority is cited. This is also a result either of custom or of poor judgment, because they cannot decide for themselves whether the conclusion of an argument is certain; and therefore, having no faith in their own judgment, as it were, they require the judgment of some recognized authority. Again there are others who want everything said to them with certitude, i.e., by way of careful rational investigation. This occurs because of the superior intelligence of the one making the judgment and the arguments of the one conducting the investigation, provided that one does not look for certitude where it cannot be had. On the other hand there are some who are annoyed if some matter is investigated in an exact way by means of a careful discussion. This can occur for two reasons. First, they lack the ability to comprehend anything; for since their reasoning power is poor they are unable to understand the order in which premises are related to conclusions. Second, it occurs because of quibbling, i.e., reasoning about the smallest matters, which bears some resemblance to the search for certitude since it leaves nothing undiscussed down to the smallest detail. Then there are some who think that, just as liberality is lacking when the smallest details are taken into account in estimating the fee for a banquet, in a similar way there is a lack of civility and liberality when a man also wishes to discuss the smallest details in the search for truth.

             335. For this reason one must be trained (174).

             He exposes the proper method of investigating the truth. Concerning this he does two things. First (174:C 335), he shows how a man can discover the proper method of investigating the truth. Second (175:C 336), he explains that the method which is absolutely the best should not be demanded in all matters ("But the exactness of mathematics").

             He says, first, that since different men use different methods in the search for truth, one must be trained in the method which the particular sciences must use to investigate their subject. And since it is not easy for a man to undertake two things at once (indeed, so long as he tries to do both he can succeed in neither), it is absurd for a man to try to acquire a science and at the same time to acquire the method proper to that science. This is why a man should learn logic before any of the other sciences, because logic considers the general method of procedure in all the other sciences. Moreover, the method appropriate to the particular sciences should be considered at the beginning of these sciences.

             336. But the exactness of mathematics (175).

             He shows that the method which is absolutely the best should not be demanded in all the sciences. He says that the "exactness," i.e., the careful and certain demonstrations, found in mathematics should not be demanded in the case of all things of which we have science, but only in the case of those things which have no matter; for things that have matter are subject to motion and change, and therefore in their case complete certitude cannot be had. For in the case of these things we do not look for what exists always and of necessity, but only for what exists in the majority of cases. Now immaterial things are most certain by their very nature because they are unchangeable, although they are not certain to us because our intellectual power is weak, as was stated above (149:C 279). The separate substances are things of this kind. But while the things with which mathematics deals are abstracted from matter, they do not surpass our understanding; and therefore in their case most certain reasoning is demanded. Again, because the whole of nature involves matter, this method of most certain reasoning does not belong to natural philosophy. However, he says "perhaps" because of the celestial bodies, since they do not have matter in the same sense that lower bodies do.

             337. Now since this method of most certain reasoning is not the method proper to natural science, therefore in order to know which method is proper to that science we must investigate first what nature is; for in this way we will discover the things which natural philosophy studies. Further, we must investigate "whether it belongs to one science," i.e., to natural philosophy, or to several sciences, to consider all causes and principles; for in this way we will be able to learn which method of demonstration is proper to natural philosophy. He deals with this method in Book II of the Physics, as is obvious to anyone who examines it carefully.