De ente et essentia

Now it remains to see how essence is found in accidents; for how it is found in all substances has been stated. And because, as was said, essence is that which is signified by a definition, they must have essence in the manner in which they have a definition. But they have an incomplete definition, because they cannot be defined unless the subject is posited in their definition; and this is because they do not have absolute being through themselves apart from a subject, but just as substantial being remains from form and matter when they are composed, so accidental being remains from an accident and a subject when the accident comes to the subject. Hence neither substantial form nor matter has a complete essence, because in the definition of substantial form too that of which it is the form must be posited, and thus its definition is by the addition of something outside its genus, just as is the definition of accidental form; hence in the definition of the soul the body is posited by the natural philosopher, who considers the soul only insofar as it is the form of a physical body.

Yet there is this difference between substantial and accidental forms: just as substantial form does not have absolute being through itself without that which it comes to, so neither does that which it comes to, namely matter; and therefore from the conjunction of both there remains that being in which the thing subsists through itself, and from them there is made one thing through itself. For this reason a certain essence results from their conjunction. Hence, although form, considered in itself, does not have the complete character of essence, it is nevertheless a part of a complete essence.

But that which an accident comes to is an entity complete in itself, subsisting in its own being; and this being naturally precedes the accident that supervenes. Therefore an accident supervening, from its conjunction with that which it comes to, does not cause the being in which the thing subsists, through which the thing is an entity through itself; rather, it causes a certain secondary being, without which the subsisting thing can nevertheless be understood to exist, just as the first can be understood without the second. Hence from an accident and a subject there is not made one thing through itself, but one thing accidentally. Therefore from their conjunction no essence results, as it does from the conjunction of form with matter; for this reason an accident neither has the character of a complete essence nor is a part of a complete essence, but just as it is an entity in a qualified sense, so it also has essence in a qualified sense.

But because that which is said to be so chiefly and most truly in any genus is the cause of those that come after it in that genus, just as fire, which is at the extreme of heat, is the cause of heat in hot things, as is said in Book II of the Metaphysics, substance, which is first in the genus of entities and has essence most truly and chiefly, must be the cause of accidents, which participate in the character of entity secondarily and, as it were, in a qualified sense. This nevertheless occurs in different ways. Since the parts of substance are matter and form, some accidents consequently belong chiefly to form and some to matter. Now there is a form whose being does not depend on matter, namely the intellectual soul; but matter has no being except through form. Hence among the accidents that follow form there is something that has no communication with matter, such as understanding, which is not through a bodily organ, as the Philosopher proves in Book III of On the Soul; but some of the consequences of form have communication with matter, such as sensation. No accident, however, follows matter without communication with form.

Among these accidents that follow matter, nevertheless, a certain difference is found. For some accidents follow matter according to the order it has to a specific form, such as male and female in animals, whose difference is reduced to matter, as is said in Book X of the Metaphysics; hence, when the animal form mentioned is removed, these accidents do not remain except equivocally. Others follow matter according to the order it has to a general form; and therefore, when the specific form is removed, they still remain in it, such as the blackness of the skin in an Ethiopian, which is from the mixture of the elements and not from the character of the soul, and therefore remains in him after death.

And because each thing is individuated from matter and placed in a genus or species through its form, the accidents that follow matter are therefore accidents of the individual, according to which individuals even of the same species differ from one another; but the accidents that follow form are properly properties of either a genus or a species. Hence they are found in all those participating in the nature of the genus or species, as the risible follows the form in man, because laughter occurs from some apprehension of the human soul. It should also be known that accidents are sometimes caused by essential principles according to a perfect act, such as heat in fire, which is always hot; but sometimes according to aptitude alone, while completion comes from an external agent, such as transparency in air, which is completed through an external luminous body. In such cases aptitude is an inseparable accident, but the completion that comes from some principle outside the essence of the thing, or that does not enter into the constitution of the thing, is separable, such as being moved and the like.

It should also be known that in accidents genus, difference, and species are taken in another way than in substances. Since in substances substantial form and matter make one thing through itself, a certain nature resulting from their conjunction, which is properly placed in the predicament of substance, concrete names signifying the composite are therefore properly said to be in a genus, as species or genera, such as man or animal. But form or matter is not in a predicament in this way except by reduction, just as principles are said to be in a genus. From an accident and a subject, however, one thing through itself is not made; hence no nature results from their conjunction to which the intention of genus or species could be attributed. Therefore concrete accidental names are not placed in a predicament as species or genera, such as white or musical, except by reduction; they are placed there only insofar as they are signified abstractly, such as whiteness and music.

And because accidents are not composed of matter and form, genus cannot be taken in them from matter and difference from form, as in composite substances; rather, the first genus must be taken from the very mode of being, according to which entity is said in different ways, according to priority and posteriority, of the ten genera of the predicaments. Thus quantity is so called insofar as it is the measure of substance, and quality insofar as it is a disposition of substance, and so with the others, according to the Philosopher in Book IX of the Metaphysics.

Differences in them, however, are taken from the diversity of the principles from which they are caused. And because proper properties are caused from the proper principles of the subject, the subject is therefore placed in their definition in place of the difference when they are defined abstractly, insofar as they are properly in a genus, as when it is said that snubness is the curvature of the nose. Conversely, it would be otherwise if their definition were taken according to the way they are said concretely: for then the subject would be placed in their definition as genus, since they would be defined in the manner of composite substances.

And if one accident is the principle of another accident, such as action, passion, and quantity are the principles of relation, the Philosopher therefore divides relation according to these in Book V of the Metaphysics. But because the proper principles of accidents are not always manifest, we sometimes take the differences of accidents from their effects, as “congregative” and “disgregative” are called the differences of color, which are caused by an abundance or scarcity of light, from which the diverse species of color are caused.

Thus it is clear how essence is found in substances and accidents, and how it is found in composite and simple substances, and how universal intentions are logically found in all these; except for the first, which is at the limit of simplicity, to which the character of genus or species, and consequently definition, does not belong because of its simplicity. Here ends and is completed this treatise. Amen.