Commentary Aristotle Metaphysics
Lecture 2. Questions on metaphysical method
The first problem concerns the things about which we raised questions in our introductory statements, namely, whether it belongs to one science or to many to speculate about the causes.
And there is also the problem of whether it belongs to this science to know only the principles of substance, or also the principles on which all sciences base their demonstrations (for example, whether it is possible to affirm and deny one and the same thing at the same time or not, and other such principles).
And if this science deals with substance, there is the question of whether one science deals with all substances, or many sciences. And if many, whether all are cognate, or whether some should be called wisdom and others something else.
It is also necessary to inquire whether sensible substances alone must be said to exist, or whether there are other substances in addition to these.
Also, whether they are unique, or whether there are many kinds of substances, as was said by those who put forms and mathematical objects between these and sensible things. As we said, then, this must be examined.
There is also the problem of whether this speculation has to do with substances alone or also with the proper accidents of substances. And we must inquire about sameness and difference, likeness and unlikeness, contrariety, priority and posteriority, and all other such things that the dialecticians attempt to treat (basing their investigations only on probabilities). For to them too it belongs to theorize about all these things. Furthermore, we must investigate all those per se accidents of these same things, and not only what each one of them is, but also whether there is one contrary for each one.
Does this science make use of all four causes?
346. Following his announced plan, the Philosopher begins to set down the problems which are encountered in establishing the truth. He divides this into two parts.
In the first, he gives these problems;
and in the second, he gives the reasons for these problems, by indicating the arguments on either side of the question, at therefore, let us discuss.
Now it was stated in book 2 that it is necessary to seek the method of a science before seeking the science itself.
Therefore, he first gives the problems which pertain to this science’s method of investigation.
Second, he gives the problems which pertain to the first principles with which this science deals, as has been stated in book 1; and this is at and we must inquire.
Now a science is concerned with two things, as was said in book 2, namely, a study of the causes by which it demonstrates and the things with which it deals.
Hence in regard to the first point he does two things.
First, he presents a problem concerning the investigation of causes.
Second, he presents several problems concerning the things with which this science deals, at and there is also the problem.
He says, then, that the first problem is one which we proposed in the issues raised at the end of book 2, which is, so to speak, the prologue to the whole of science. It is whether a study of the four causes in their four genera belongs to one science or to many different sciences. And this is to ask whether it belongs to one science, and especially to this science, to demonstrate by means of all the causes, or rather whether some sciences demonstrate by one cause and some by another.
Does it consider both principles of substance and principles of knowledge?
347. And there is also the problem. Here he raises problems about the things that this science considers.
First, he inquires about the things that this science considers about substances;
second, about the things that this science considers about accidents, at there is also.
Concerning the first he does two things.
First, he raises questions about the science itself, which is about substance;
second, about substances themselves, at it is also necessary.
In regard to the first he raises three questions.
For if it is supposed, from what was said in book 1, that this science considers first principles, the first question here will be whether it belongs to this science only to know the first principles of substances, or also to consider the first principles of demonstration, by means of which all sciences demonstrate. For example, should this science consider whether it is possible to affirm and deny one and the same thing at the same time or not? And the same thing applies to the other first and self-evident principles of demonstration.
Is its subject all substances, or do different sciences consider different substances?
348. And if this science considers substance as the primary kind of being, the second question is whether there is one science which considers all substances, or whether there are many sciences which consider different substances. For it seems that there should be many sciences which consider many substances.
Is it distinct from other sciences?
349. And if there are many sciences which consider many substances, the third question is whether all are cognate, that is, whether all belong to one genus, as geometry and arithmetic belong to the genus of mathematical science, or whether they do not, but some to the genus of wisdom and some to another genus (for example, to the genus of natural philosophy or to that of mathematical science). For, according to the first point of view, it seems that they do not belong to one genus, since material and immaterial substances are not known by the same method.
Are there immaterial substances, and of what kind?
350. It is also necessary. Here he adds to the number of questions about substance, and he does this by raising two questions.
The first question is whether sensible substances alone must be held to exist, as the philosophers of nature claimed, or whether there are in addition to sensible substances other immaterial and intelligible substances, as Plato claimed.
351. And if there are some substances separate from sensible things, the second question is whether they are unique, that is, whether they belong only to one genus, or whether there are many genera of such substances. For certain men, understanding that there is a twofold abstraction (namely, of the universal from the particular, and of the mathematical form from sensible matter) held that each genus is self-subsistent. Thus they held that there are separate substances which are subsisting abstract universals, and between these and particular sensible substances they placed the objects of mathematics—numbers, continuous quantities, and figures—which they regarded as separate subsisting things.
Concerning the questions which have now been raised, then, it is necessary to investigate them below.
He does this first by arguing both sides of the question, and second by determining its truth.
Does this science consider accidents or properties of substance?
352. There is also the problem. Here he asks whether this science’s investigations extend to accidents, and he raises three questions.
The first is whether this science, seeing that it is called the philosophy of substance, speculates about substance alone, or whether it also speculates about the proper accidents of substance. For it seems to be the office of the same science to consider a subject and the proper accidents of that subject.
How does it differ from logic in considering these things?
353. The second question is whether this science considers certain things that seem to be proper accidents of being and which belong to all beings, namely, sameness and difference, likeness and unlikeness, contrariety, priority and posteriority, and all others of this kind which are treated by the dialecticians, who deal with all things. However, they do not examine such things according to necessary premises but according to probable ones. For from one point of view it seems that, since these accidents are common ones, they pertain to first philosophy. But from another point of view it seems that, since they are considered by the dialecticians (whose office it is to argue from probabilities), an examination of them does not belong to the consideration of the philosopher (whose office it is to demonstrate).
Does it consider how these accidents are inter-related?
354. And since certain proper attributes naturally flow from these common accidents of being, the third question is whether it is the function of the philosopher to consider in regard to the common accidents only their quiddity, or also their properties (for example, whether there is one opposite for each one).