Lecture 30 — Imagination: what it is

But since it can happen that, one thing moving, another is moved by it; and imagination seems to be a movement, and to arise not without sensation and in sentient beings and to be of such objects as are sensed; and since a motion may be caused by actual sensation, and such necessarily resembles sensation, then imagination will be just this movement, never originated without sensation, nor capable of existing in non-sentient beings, enabling its possessor to act and to be acted upon in many ways, and being itself both true and false.

This happens because sense-perception is true of its own proper objects or has the least possible amount of falsehood; but second, it bears on that in which these qualities inhere, and here it can right away be deceived. For it is not deceived about a thing being white or not, but it is deceived about whether the white is this thing or something else. Third, there is sensation of the common and consequent things, the accidents in which the proper qualities inhere (I mean such as movement and magnitude, which are accidental to sense-objects), and about these, deception very easily arises in sensing.

The movement derived from the act of sensation, however, differs from the sensation by which these three sensings occur. Although the first is true, the sensation itself being present, the others can easily be false, whether sensation be present or not, and especially when the sense-object is distant.

If, therefore, nothing except imagination possesses what has been described, then the statement is true, namely that imagination is a movement produced by sensation in act.

Since sight is the greatest sense, imagination has taken its name from light, as there is no seeing without light.

And since these images dwell within and are like the senses, animals do many things in accordance with them; some animals because they do not have understanding, namely, beasts, but some too, i.e., men, when their understanding is for a time veiled by passion, or sickness, or sleep.

Let what has been stated suffice, therefore, as to what imagination is and on account of what it exists.

655. But since it can happen that (428b10). After showing that imagination is not one of those four into which the earlier philosophers divided knowledge, the Philosopher now asks: what is imagination? And he does two things.

First, he shows what imagination is.

Second, he explains the reason for the things that pertain to imagination, at this happens because (428b17; [660]).

And with a view to studying what imagination is, he lays it down that anything moved may itself move something else (recalling the argument in Physics 8, where it is shown that there are two kinds of mover, that is, the immobile mover, and the moved mover, that is, what moves another in its being in motion). (Aristotle, Physics 8.5, 256a4–13; cf. Aquinas, Commentary on Physics, bk. 8, lect. 9.)

656. Then he suggests that imagination is a sort of movement: that just as the sensing soul is moved by sensible objects, so, in imagining, it is moved by certain appearances called “phantasms.”

657. Next, he suggests an affinity between the imagination and the senses, in that imagination seems to arise not without sensation, and it is found only in sentient beings, that is, in animals, and that it bears only on things that are sensed; for things that are only intelligible do not fall within imagination.

658. Then he suggests that a motion may be caused by actual sensation, which becomes in fact manifest from what was first laid down, that when a thing is moved, another thing might be moved by it. Actual sensation arises from the fact that a sense is being moved by sensible objects, so the sense in act causes some movement; and from this it is also manifest that the motion caused by the act of sensation must necessarily be like the sensation; for every agent is a cause of its own likeness. Whence that which, being moved, moves another, must also cause a motion like itself.

659. And this leads him to the conclusion that imagination is a certain movement caused by the senses in their act of sensing, and this motion is never originated apart from sensation, nor can it exist in things that do not sense. For if there is any movement caused by actual sensation like the motion of sensation, and nothing other than imagination alone is found to be such, imagination must be this motion. And since it is a motion caused by sensation and is like it, it follows that what has imagination is able to act and to be acted upon in many ways. And it can be both true or false, as we shall see.

660. Next, at this happens (428b17), he gives reasons for the characteristic properties of imagination, using the above analysis. And about this he does three things.

First, he gives a reason for his assertion that imagination is sometimes true and sometimes false.

Second, he explains why it is called by this name, at since sight is the most prominent sense (429a2; [668]).

Third, he explains why he said that animals do many things according to their imaginations, at and since these images dwell within (429a4; [669]).

First, then, he notes that this, that is, that imagination is sometimes true and sometimes false, happens because the sense, due to whose act the imagination is caused, stands in diverse relations to truth and falsity, insofar as it is related to diverse things.

661. For, in the first place, sense-perception is always true with respect to its proper objects, or at least it holds the minimum of falsehood; for natural powers do not fail in the activities proper to them, except for the lesser part, on account of some corruption. Thus, only in a minority of cases do the senses fall short of a true judgment of their proper objects, and then only through some corruption of the organ, for example, when people sick with fever taste sweet things as bitter because their tongues are ill-disposed.

662. Second, the senses have also their accidental sense-objects, and here right away they are deceived. For the sense is not deceived in this, namely, that the thing that is seen is white, but in whether the white thing is this or that thing (for example, whether it is snow or flour or something like this), here it can right away be deceived, especially by things at a distance.

663. Third, there is sensation of common sensibles, which are consequent to the subjects in which are the accidents that are the proper sensibles. Thus, magnitude and movement, as common sensibles, are accidents of the sensible bodies. And deception very easily occurs for these, since in their case judgment varies dependent on distance, for a thing seen further away is seen less.

664. The movement of imagination, being derived from the act of sensation, differs from these three sensings, that is, the acts of the senses, as an effect differs from its cause. On account of this also, because an effect is weaker than its cause, to the extent that something is more distant from the first agent, so too does it receive less of the power and likeness of it; therefore imagination is even more liable than are the senses to fall into error, which consists in a dissimilarity between the sense and its object. For falsehood in the senses consists in receiving a sensible form as other than it is in the sensible object. I mean other in species, not in matter (for example, if a sweet savor is received in the tongue as bitter); for in matter there is always a difference between the form as received in the sense and the form as in the object. It follows first, from what we have said, that a motion of imagination that arises from a sensation of the proper sense-objects is for the most part true; I mean, at least, so long as the sensible object is present, when the movement of imagination is simultaneous with the movement of sensation.

665. But when the movement of imagination occurs in the absence of sensation, we can be deceived, even with regard to proper sensibles. For we may imagine absent black things as white. But the others, that is, the movements of imagination caused by the sensation of accidentally sensible things or of common-sensibles, can be false whether the sensible object be present or not; although they are especially liable to be false in the absence of the sensible object, when it is distant.

666. From this argument, he then draws a conclusion touching his main contention: namely, if nothing possesses what has been described, except the imagination, and imagination has what was said, then imagination is the movement produced by sensation in act.

667. Whether this movement also requires some potency other than the sensitive power is a question which Aristotle leaves unanswered.

Since, however, diverse acts imply diverse potencies, and diverse movements connote diverse receivers of movement (for the moving thing moves something other than itself), it seems necessary to posit an imaginative (or fantasy) power distinct from the senses.

668. Next, at since sight (429a2), he explains the reason for the name phantasia (imagination). Note that phos is the Greek for light, whence comes phanos, that is, “appearance” or “enlightening,” and phantasia. He says, then, that, because sight is the chief among the senses, being more spiritual (as we have seen already), and knowing a wider range of objects than any other, therefore imagination, which is caused by actual sensation, has taken its name from light, as there is no seeing without light. (Lect. 14, nn. 417–18, 403–12.)

669. Then, at and since these images (429a4), he explains why animals act and are acted upon according to imagination. Images, he says, dwell within, that is, they endure, even in the absence of sensible objects, and are like the senses in act; therefore, just as actual sensation moves the appetite at the presence of the sensible object, so even do images in the absence of the sensible object. And therefore he says that animals do many things in accordance with images. Nevertheless, this happens through their lack of understanding, since when intellect is present, being a higher power, its judgment prevails in practice.

670. Hence, so long as the intellect is not in command, animals act according to imagination: some animals because they do not have understanding at all, for example, the beasts, but some because they have a veiled intellect, for example, in men. And this happens in three ways:

when they fall into some passion, such as anger, desire, fear, etc.;

when something is so strong that it clouds the intellect, which sometimes happens through some infirmity, as is clear in delirium or in a rage;

and when they are asleep and dreaming.

In these cases, it is possible for the intellect to not prevail over the imagination, with the result that men follow their imaginary representations as true.

In conclusion, he says that he has now stated on imagination (429a8) what it is and its cause.