Cursus Philosophicus Thomisticus, Prima Pars Artis Logicae

For p. 136 b 13.

OBJECTIONS ARE RESOLVED.

A common argument is usually made against the whole definition of definition: the same thing cannot at once be defined and be a definition, for then it would be more known and less known than itself. Therefore, if we define definition, the definition itself will be the defined thing, since it is what is defined. And again it is a definition, since this is its nature and essence; therefore it is at once a definition and the defined thing.

It is confirmed because a definition is said to be convertible with its defined thing, but the definition given here is not convertible with definition; therefore. The minor is proved: this definition is a particular definition contained under definition in general; therefore it cannot equal and be convertible with that general definition, since it is something contained under it. Consequently, it defines itself, and thus the argument returns: the defined thing and the definition are the same, just as if Peter were to define a human being, his definition would not be said to be convertible with a human being.

I ANSWER: Distinguish the proposition “The defined thing and the definition are formally the same”: denied. “The definition is formally the same thing (because this is its essence), and the defined thing is the same denominatively (insofar as it is compared with its definition)”: granted. For it is very common for one second intention to be such formally and to be another denominatively. For example, genus is formally the intention of genus, and denominatively a species of the predicables, as we shall say in Logic.

To the confirmation, the answer is that the definition of definition is said to be convertible with its defined thing formally, insofar as it is what is defined by it; but insofar as it regards definition in general as its genus, it is not convertible with it, but is contained under it. Peter, however, does not regard a human being as what he defines, but precisely as a superior species.

Second argument: Definition belongs to the first operation of the intellect, but an expression belongs to the second, as we said in the preceding article; therefore, “expression” is incongruously posited as its genus.

The major is established by Thomas, Sentences I, d. 19, q. 5, a. 1, ad 7, who says that “truth and falsity are not found in the first operation and its sign, which is a definition.”¹

It is confirmed: A definition is a mode of knowing; a mode of knowing does not have an expression as its genus; therefore, neither does definition.

The minor is proved: what is placed under some genus must be placed determinately under one of its species; but a mode of knowing is not in any determinate species of expression; therefore, it does not have expression as its genus. The major is proved: a mode of knowing can be found in both a perfect and an imperfect expression; therefore, it is not determinately in any one species of expression.

I ANSWER that “expression” is understood to include an imperfect expression, which materially coincides with a complex term; for nothing more is required for a mode of knowing, as was said above. Thus, it is not contradictory for a definition to be found in the first operation of the intellect, namely, when it is taken in the force of a complex term, and because its object is something simple, the quiddity of a thing, although it is explained compositionally. It is nevertheless defined through an expression because it is a mode of knowing, and a mode of knowing is commonly defined through an expression; also, definition can be held in the force of an expression if it is taken in the mode of a whole, although, when taken in the force of a complex term, it pertains to the first operation.

To the confirmation, the response is that the major of the second syllogism is distinguished: “What is placed formally and directly under a genus must be placed determinately under one of its species”: the major is granted. “What pertains to a genus only materially or consequently”: denied. For example, a statue is placed materially in stone or wood, because it belongs to a natural genus only materially, that is, as made from it. It does not follow that it must be constituted determinately in this stone or that wood, because it does not regard stone or wood as its genus, but as its matter; thus it can be made from any stone or any wood without any determination. Similarly, white is determinately a body, but not determinately animate or inanimate; wisdom or intelligibility is determinately a being, but is not determinately created or uncreated, because it can follow upon either. Therefore, expression is not the genus of a mode of knowing, but the matter from which it is formed under another logical art, namely, as an artificial mode of making the unknown manifest.

Third argument: Definition cannot be found outside a proposition; therefore, the first conclusion is false.

The antecedent is proved: Definition and the defined thing are relatives; therefore, definition must actually regard and be compared with the defined thing in order to be a definition. But when it is not predicated of the defined thing, it does not regard it in act, but in potency; therefore, it is not actually a definition.

It is confirmed: A definition is not actually accidental or essential except through an actual comparison with such a defined thing; therefore, it is not absolutely a definition except through a comparison with the defined thing. The antecedent is proved: this definition, “an animal apt to laugh,” is essential if applied to what is capable of laughter, but accidental if applied to a human being. Therefore.

I ANSWER the argument: The consequence of the second enthymeme is distinguished: “It must actually regard and be compared with the defined thing under the aspect of subject or predicate”: denied; “under the precise aspect of what is defined”: granted. In this way, a definition regards its defined thing even when it is not actually predicated of it. So a name regards what it signifies, matter regards form, and every potency its object, even if it does not actually exercise its causality and operation upon it. For actually regarding is one thing, actually causing or predicating another. Outside a proposition, a definition regards what it defines; from this it has the character of a definition even if it is not actually predicated.

To the confirmation, the answer is in the same way: a definition is essential or accidental not through predicative application to what it defines in the role of subject or predicate, but through the simple regard and relation it has to it as what is defined, which is found outside a proposition.

OBJECTIONS AGAINST THE CONDITIONS OF DEFINITION.

First: Genera, differences, property, and individuals, especially incorruptible ones, are defined by their own definitions; therefore, it is not necessary for a definition to consist of genus and difference.

The consequence is proved: if this were necessary, only a species would be definable, since only a species consists of genus and difference; but all the things listed above are defined; therefore.

I ANSWER by absolutely denying the antecedent. For only a species is properly definable, as Thomas teaches in Metaphysics VII, lect. 3.² If genera are supreme, they are not defined but described through a determinate analogous concept, not through a difference but through a mode. If they are subordinate, they are also species, and insofar as they are such, they are defined. Difference, property, and accident are defined only insofar as they have some nature that is reduced to a species. But if they are taken as parts, not as complete natures—as differences are—they are not defined, but described. Individuals as such, formally and in their actual exercise, are not definable or knowable, even if incorruptible, formally as individuals. If they are defined, it is through the nature of their species or by taking individuation in general. Hence Thomas, in the cited place, lect. 15,³ asserts that the singular lacks a definition not only because it is corruptible and material, but because it is singular: as such, it does not express a quiddity, which is the object of definition, but a mode or modification of quiddity.

Again: Relatives are simultaneous in nature and cognition; therefore, one is not better known than the other, since what is better known is prior in cognition. Yet one relative is defined through the other; therefore, it is not required that a definition be better known than what it defines.

I ANSWER IN TWO WAYS: First, it is not required that each part of a definition be better known than what it defines, but that the whole definition taken together be so; a relative, however, is only one part in the definition of a relative. Second, grant that the parts too must be better known; then explain that they are either positively or negatively better known. A relative is not positively better known or prior to its correlative, but it is negatively better known, insofar as without it the relative itself remains obscure and unknown.

Finally, demonstration and science manifest the nature of a thing; therefore, the definition of definition belongs to other things as well. If you say that demonstration proves properties or attributes, against this: therefore, it will manifest the nature at least in the way that a descriptive definition does, since the latter concerns properties.

I ANSWER: The antecedent is denied. For definition is one of the principles or items of prior knowledge for demonstration, as is said in Posterior Analytics I, ch. 1.⁴ Demonstration manifests that attributes belong to a subject, but it does not do so in the manner of a descriptive definition: the latter does not prove that attributes belong to a subject, but, presupposing this, explains it in a simple way through those attributes and manifests its nature accidentally, without proving or demonstrating it.

WHAT THE PROXIMATE AND REMOTE DEFINED THING ARE.

In the text we said that the name of the thing defined can be called the proximate defined thing, while the thing signified by it can be called the remote defined thing. The reason is that the name is a sign that represents and brings near, or applies, the matter that can be defined. This sign, in turn, remains declared consequently: when the thing defined and the signified thing have been declared, the sign is also declared and explained. Hence the name, in this respect, can be called the proximate defined thing, even if it is not the thing most immediately manifested.

Others add that the quiddity or nature defined can be called the proximate defined thing, while the attribute connected and joined to the essence can be called the remote defined thing. But they assert this falsely, because only that is a defined thing which is explained and declared by a definition; for the defined thing and the definition are related. But in an essential definition the attribute is not the thing defined; rather, it is the nature. Likewise, in a descriptive definition the attribute is not the thing that is defined and made known; rather, the nature is made known through the attribute. Therefore, an attribute can never be called what is defined except when it is defined separately from the nature.

If it is objected that the name, too, is not the thing defined, yet it is called the proximate defined thing, you will say that the name itself is declared and explained at least virtually, though not formally.

Against this: When the nature is declared, its attribute is also declared virtually; therefore, this suffices for it to be called the defined thing, at least remotely. Again, the Philosopher, Posterior Analytics II, text 7,⁵ asserts that a definition of the name and a definition of the thing cannot be the same; therefore, by one and the same definition one thing cannot be defined as the proximate defined thing and another as the remote one.

TO THE ARGUMENT: The answer there was sound. To the reply: the antecedent is denied; an attribute is related to a nature as an effect that follows it, not as a sign representing it, as a name does. When the nature of a cause is declared, its effect can still remain unknown; but when the signified thing is declared, the sign cannot remain unknown, since it actually and in the exercise of signifying represents the thing signified. To the Philosopher, the answer is that he is speaking of a definition of the thing and a definition of the name, which are such in themselves and directly, and each explains its own defined thing. Aristotle does not deny that, once the thing itself has been defined, the name itself can consequently and indirectly be explained as the proximate defined thing in the mode of a sign, not in the mode of matter being defined.