Aquinas Day By Day


Aquinas’s topic:  relation 3

Scripture:  “When the Son of man comes in his glory, and all the angels with him, he will sit upon his glorious throne, and all the nations will be assembled before him.  And he will separate them one from another, as a shepherd separates the sheep from the goats.”  Matthew 25: 31-2

Aquinas’s text:  Sententia super Metaphysicam, Bk. 5, lec. 17

Here Br. Thomas develops his ideas about the third sense of relation, which is important for understanding knowledge.  This kind of relation is non-reciprocal and is exemplified in the relation of knower to known object or sensor to sensed object.  Knowing and sensation affect the person or animal who knows, but they have no effect at all on the thing known or sensed.  These relations therefore differ, depending upon whether the relation moves from knower to known object or from the known to the knower. The latter is the kind of relation at issue here.

From Aquinas’s commentary on the Metaphysics:

(3) Then [Aristotle] proceeds to the third kind of relation and says that the third kind is different from the previous kinds, because in the previous kinds of relation each is called relative because it is referred to something else, not because something else is referred to it.  For double is related to half, and the reverse; and also father is related to son, and the reverse.  But in this third sense something is called relative only because something is referred to it.  For example, it is clear that the sensible and the knowable or intelligible are said to be relative because other things are referred to them.  For something is called knowable for this reason, that knowledge is had of it.  Likewise, something is called sensible because it can be sensed.

Consequently, they are not said to be relative because of something that is part of them, a quality or quantity or action or passion, as is the case in the earlier kinds of relations, but only because of the actions of other things, though these actions do not terminate inside them.  For if seeing were an action of the person seeing that proceeds all the way to the thing seen, as heating does proceed all the way to the thing heated, then just as the thing heated is referred to the thing that heats, so too would the visible thing be referred to the person who sees.  But seeing and understanding and actions like them remain in the agent, they are not transient actions proceeding over to things affected by them, as Aristotle says in Book IX. Consequently, the visible and knowable objects do not undergo something when they are known or seen.  This is why they are not referred to other things but others are referred to them. The same thing is true for all other cases where something is said to be relative because of the relation of something else to it, for example, being to the right or left of a column.  Since right and left designate the beginning of motion in animate things, they cannot be attributed to a column or any inanimate thing except in so far as animate things are related to it. For example, a column is called “right” because a human is to the left of it.  The same thing holds true of image in relation to its exemplar, and of a denarius, which determines the price of a sale.  In all these cases, the whole reason for the referring between the two extremes depends upon only one of them.  Therefore, all of these kinds of examples are related in a way comparable to measurable and measure.  For everything is measured by that on which the thing depends.

One must understand, then, that even though, when we only look at words, knowledge seems to refer to both the knower and the known, for we say “the knowledge of the knower” and “the knowledge of the object known,” and understanding seems to refer to both the person who understands and the understood object, nevertheless, understanding when considered as a relation is not said to be relative to him whose thought it is as its subject. ... Likewise, in the case of seeing it is clear that it is not said to be relative to the one who sees but to its object, which is color. ... Although it is correct to say that sight is of the one who sees, sight refers to the person who sees not as seen but as an accident or a power in the one who sees.  For relation concerns something external, not the subject except in so far as it is an accident.

[Introductions and translations © R.E. Houser]