LECTURE 6 (195 a 28-b 30)

CONCERNING THE DIFFERENT MODES OF CAUSING AND THOSE THINGS WHICH ARE CONSEQUENT UPON THESE DIFFERENT MODES OF CAUSING

             187. After the Philosopher has distinguished the species of causes, he here distinguishes the various modes of causes in respect to the same species of cause.

             Concerning this he makes two points. First he distinguishes the different modes of causes. Secondly, where he says, 'The difference is . . .' (195 b 17), he treats certain consequences of this distinction.

             Concerning the first part he makes two points. First he distinguishes the different modes of causes, and secondly, where he says, 'All these various . . .' (195 b 13), he reduces them to a certain number.

             Concerning the first part he distinguishes the modes of causes according to four divisions.

             He says, therefore, first that the modes of causes are numerous, but if they are reduced to headings, either under some highest, or under some common aspect, they are found to be fewer. Or 'headings' may be taken as a combination, for it is obvious that combinations of the modes are fewer than the modes.

             188. Therefore the first division or combination of modes is that in the same species of cause one cause is said to be prior to another, as when we understand that the more universal cause is prior. Thus the doctor is the proper and posterior cause of health, whereas the artisan is the more common and prior cause. This is in the species of efficient cause. And the same thing is true in the species of formal cause. For the proper and posterior formal cause of the octave is the proportion of the double, whereas the more common and prior is the numerical proportion which is called multiplicity. And in like manner a cause which contains any cause in the community of its extension is a prior cause.

             189. It must be noted, however, that the universal cause and the proper cause, and the prior cause and the posterior cause, can be taken either according to a commonness in predication, as in the example given about the doctor and the artisan, or according to a commonness in causality, as if we say the sun is a universal cause of heating, whereas fire is a proper cause. And these two divisions correspond to each other.

             For it is clear that any power extends to certain things insofar as they share in one nature [ratio], and the farther that that power extends, the more common that nature [ratio] must be. And since a power is proportioned to its object according to its nature [ratio], it follows that a higher cause acts according to a form which is more universal and less contracted. And this can be seen in the order of things. For to the extent that among beings some things are superior, to that extent they have forms which are less contracted and more dominant over matter, which contracts the power of form. And so that which is prior in causing is found to be prior in some way under the aspect [ratio] of a more universal predication. For example, if fire is the first in heating, then the heavens are not only the first in heating but also the first in producing alteration.

             190. He gives the second division where he says, 'Another mode of causation . . .' (195 a 33).

             He says that just as per se causes are divided into prior and posterior or common and proper, so also are per accidens causes.

             For besides per se causes there are per accidens causes and their genera. Thus Polycletus is a per accidens cause of the statue, while the sculptor is a per se cause. For Polycletus is a cause of statue insofar as he happens to be a sculptor. And in like manner those things which contain Polycletus in their commonness, e.g., man and animal, are per accidens causes of statue.

             Moreover it must be noted that among per accidens causes some are closer to the per se causes and some are more removed. For everything which is joined to the per se cause but is not of its nature [ratio] is called a per accidens cause. Now a thing can be closer to the nature [ratio] of the [per se] cause or more removed from it, and to this extent the per accidens causes are closer or more removed. Thus, if a sculptor happens to be white and musical, the musical is closer, because it is in the same subject in respect to the same thing, i.e., in respect to the soul in which are both [the art of the] musician and the art of statue making. But the subject itself is still more closely related than the other accidents. Thus Polycletus is closer than white or musical, for these latter are not joined to this sculptor except through the subject.

             191. He gives the third division where he says, 'All causes . . .' (195 b 4).

             He says that besides the causes properly so called, i.e., the causes per se and the causes per accidens, some things are said to be causes in potency, as being able to operate, while other things are actually operating causes. Thus either the builder in habit or the builder in act can be called the cause of the building of a house.

             192. And just as causes are distinguished according to the above mentioned modes, so also the things of which they are the causes are distinguished. For one thing is caused posteriorly and more properly, and another priorly and more commonly. Thus something might be called the cause of this statue, or of statue in general, or still more commonly it might be called the cause of an image. And likewise something might be called the moving cause of this bronze, or of bronze in the universal, or of matter.

             So also, in per accidens effects, it can be said that one thing is more common and another less common. An effect is said to be per accidens when it is joined to a per se effect and is outside its nature [ratio]. Thus the per se effect of cooking is delectable food, but the per accidens effect is healthful food. However the converse is true of medicine.

             193. He gives the fourth division where he says, 'Again we may use . . .' (195 b 10).

             He says that sometimes per se causes are taken as a complex with per accidens causes, as when we say that neither Polycletus, who is a per accidens cause, nor the sculptor, who is the cause per se, is the cause of the statue, but rather that the sculptor Polycletus is the cause.

             194. Next where he says, 'All these various uses . . .' (195 b 13), he reduces the above mentioned modes to a certain number.

             He says that the above mentioned modes are six in number, but each of them is used in two ways. These are the six modes: the singular and the genus, which above he called the prior and the posterior, the accident and the genus of the accident, the simple and the complex. And each of these is divided by potency and act; and so all the modes become twelve. He distinguishes all the modes by potency and act because what is in potency is not simply.

             195. Next where he says, 'The difference is . . .' (195 b 17), he treats three things which follow from the distinction of modes just made.

             The first point is that causes in act and causes in potency differ as follows. Causes operating in act exist and do not exist simultaneously with those things of which they are the causes in act. For example, if we take singular causes, i.e., proper causes, then this healer exists and does not exist simultaneously with him who becomes healed, and this builder exists simultaneously with that which is built. But this is not true if we take causes in act which are not proper causes. For it is not true that builder exists and does not exist simultaneously with that which is built. For it can happen that the builder is in act but this building is not being built, but some other. But if we take the one who is building this building, and if we take this building insofar as it is being built, then it is necessary that when one is posited, the other must be posited also, and when one is removed the other is removed. But this does not always happen in regard to causes which are in potency. For a home and the man who built it are not corrupted simultaneously.

             And thus it follows that just as inferior agents, which are causes of the coming to be of things, must exist simultaneously with the things which come to be as long as they are coming to be, so also the divine agent, which is the cause of existing in act, is simultaneous with the existence of the thing in act. Hence if the divine action were removed from things, things would fall into nothingness, just as when the presence of the sun is removed, light ceases to be in the air.

             196. He sets forth the second point where he says, 'In investigating the cause . . .' (195 b 21). He says that it is necessary to seek in natural things the first cause of each thing, just as we do in artificial things. So if we should ask why it is that a man builds, we answer 'because he is a builder'. Likewise, if we ask why he is a builder, we answer, 'because he possesses the builder's art'. And here the inquiry stops, because this is the first cause in this order. Hence in natural things we should proceed to the first cause. This is so because the effect is not known unless the cause is known. Hence if the cause of an effect is also the effect of some other cause, then it cannot be known unless its cause is known, and so on until we arrive at a first cause.

             197. He sets forth the third point where he says, 'Further generic effects . . .' (195 b 25). Effects should correspond proportionally to causes so that general effects be referred to general causes and singular effects to singular causes. For example, if it is said that the cause of statue is sculptor, then the cause of this statue is this sculptor. In like manner effects in potency should correspond to causes in potency and effects in act to causes in act.

             And finally in summary he concludes that this is a sufficient treatment of the species and modes of causes.