Commentary Aristotle Metaphysics
Lecture 8. Are genera principles of things?
Concerning the principles of things there is the problem of whether genera must be regarded as the elements and principles of things, or rather the first things of which each thing is composed inasmuch as they are intrinsic.
Just as the elements and principles of a word seem to be those things of which all words are first composed, but not word in common. And just as we say that the elements of diagrams are those things whose demonstrations are found in the demonstrations of others, either of all or of most of them.
Furthermore, those who say that the elements of bodies are many, and those who say that they are one, call the things of which bodies are composed and constituted their principles, as Empedocles says that fire and water and those things that are included with these are the elements from which existing things derive their being. But he does not speak of them as the genera of existing things.
And again if anyone wished to speculate about the nature of other things, in finding out in regard to each (a bed, for example) of what parts it is made and how it is put together, he will come to know its nature. And according to these arguments, genera are not the principles of existing things.
But if we know each thing through definitions, and genera are the principles of definitions, genera must be the principles of the things defined.
And if in order to acquire scientific knowledge of existing things it is necessary to acquire scientific knowledge of their species, according to which they are said to be beings, then genera are the principles of species.
Moreover, some of those who say that the elements of existing things are the one or being or the great and small seem to use these as genera.
But it is not possible to speak of principles in both ways; for the meaning of substance is one. Therefore, a definition by means of genera will differ from one which gives the intrinsic constituents.
Again, if genera are the principles of things in the fullest sense, there is the question of whether the first genera must be thought to be principles, or those which are lowest and are predicated of individual things. For this also raises a problem.
For if universals are the principles of things to a greater degree, evidently these must be the highest genera, because it is most properly these which are predicated of all existing things. Therefore, there will be as many principles of existing things as there are first genera. Hence being and unity will be principles and substances, for it is these especially which are predicated of all existing things. It is impossible, however, that unity or being should be a single genus of existing things, for it is necessary both that the differences of each genus exist and that each be one. But if unity and being are not genera, neither will they be principles, if genera are principles.
Further, those things that are intermediate and are taken along with differences will be genera down to individuals. But some seem to be such, whereas others do not. Again, differences are principles to a greater degree than genera. If they are principles, principles will be infinite in number, so to speak. And this will appear in another way also if one holds that the first genus is a principle.
But, on the other hand, if unity is a specific principle to a greater degree, and unity is indivisible, and everything indivisible is such either in quantity or in species, and what is indivisible in species is prior, and genera are divisible into species, then it will be rather the lowest predicate which is one. For man is not the genus of particular men.
Further, in the case of those things to which prior and subsequent apply, it is not possible in their case that there should be something which exists apart from them.
For example, if the number two is the first of numbers, there will not be any number apart from the species of numbers, nor, likewise, any figure apart from the species of figures.
But if the genera of these things do not exist apart from the species, then in the case of other things the teaching will be that there are genera apart from the species; for of these things there seem especially to be genera. But among individual things one is not prior and another subsequent.
Further, where one thing is better and another worse, that which is better is always prior; so that there will be no genus of these things. From these considerations, then, it seems that it is the terms predicated of individuals, rather than genera, which are principles.
But again it is not easy to state how one must conceive these to be the principles of things. For a principle or cause must be distinct from the things of which it is the principle or cause, and must be able to exist apart from them. But why should one think that anything such as this exists apart from singular things, except that it is predicated universally and of all things? But if this is the reason, then the more universal things are, the more they must be held to be principles. Hence the first genera will be principles of things.
What is the difference between genera and elements?
423. Having debated the questions which were raised about substances, the Philosopher now treats dialectically the questions which were raised about principles. This is divided into two parts.
In the first, he discusses the questions which asked what the principles of things are;
in the second, the questions which asked what kind of things the principles are, at again, there is the problem.
In the first part of this division he discusses two questions:
first, whether universals are the principles of things;
second, whether any principles are separate from matter, at but there is a problem.
In regard to the first he discusses two questions, of which the first is whether genera are the principles of things.
The second asks which genera these are, whether the first genera or the others, at again, if genera.
In regard to the first he does two things:
first, he raises the question;
second, he treats it dialectically, at just as the elements.
The first question has to do with the principles of things. Is it necessary to accept or believe that those genera which are predicated of many things are the elements and principles of things, or rather that those parts of which every single thing is composed must be called the elements and principles of things?
But he adds two conditions, one of which is inasmuch as they are intrinsic, which is given in order to distinguish these parts from a contrary and a privation. For white is said to come from black or the non-white, although these are not intrinsic to white. Hence they are not its elements.
The other condition is what he calls the first things, which is given in order to distinguish them from secondary components. For the bodies of animals are composed of flesh and nerves, which exist within the animal, yet these are not called the elements of animals, because they are not the first things of which an animal is composed, but rather fire, air, water, and earth, from which flesh and nerves derive their being.
424. Just as the elements. Here he treats this question dialectically, and in regard to this he does three things.
First, he shows that the first things of which anything is composed are its principles and elements.
Second, he argues the opposite side of the question, at but if we know.
Third, he rejects one answer by which it could be said that both of these are the principles and elements of things, at but it is not.
In regard to the first he gives three arguments.
The first of these proceeds from natural phenomena, in which he makes his thesis evident by two examples.
He first gives the example of a word, whose principle and element is not said to be the common term “word,” but rather the first constituents of which all words are composed, which are called letters.