LECTIO SIX

             § 655. After showing that imagination is not one of those four activities into which the earlier philosophers divided knowledge, the Philosopher now asks: what is imagination in itself? And he does two things. First, he says what imagination is; secondly, he explains its properties, at 'This happens because'. And with a view to defining imagination he lays it down that anything moved may itself move something else (recalling the argument in the Physics, Book VIII, where it is shown that there are two kinds of mover, one that is itself without movement, and one that moves another through being moved itself).

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

             § 657. Next, he suggests an affinity between the imagination and the senses, in that imagination presupposes sensation and is found only in sentient beings or animals; and further, that it bears only upon things sensed, and in no way on things purely intelligible.

             § 658. Then he suggests that the act of sensation can give rise to a sort of movement, in accordance with the principle first laid down, that a thing moved may move another. Actual sensation is a being moved by a sensible object; and the movement of the actuated sense itself causes another movement which, as it proceeds from sensation, must resemble sensation; for every agent as such is a cause of its own likeness. And that which, being moved, moves another, must cause a motion similar to its own.

             § 659. And this leads him to the conclusion that imagination is a certain movement caused by the senses in their act of sensing. It cannot exist without sensation, nor in insentient beings. If there is any movement caused by actual sensation, it must resemble sensation, and imagining is the only activity of this kind. Hence it must be the movement in question. And, being such, it can give occasion to the imagining subject for a variety of actions and passions. And it can be either true or false, as we shall see.

             § 660. Next, at 'This happens', he gives reasons for the characteristic properties of imagination, using the above analysis: (a) he gives a reason for his assertion that imagination is sometimes true and sometimes false; (b) he explains why it is called by this name; and (c) he explains why he said that animals are largely governed by their imaginations.

             (a) First, then, he notes that the reason why imagination is sometimes true and sometimes false is implicit in the statement that its source is the act of the exterior sense; for the latter is related to truth in different ways, according to its varying relation to objects.

             § 661. For, in the first place, sense-perception is always truthful with respect to its proper objects, or at least it incurs, with respect to these, the minimum of falsehood; for natural powers do not, as a general rule, fail in the activities proper to them; and if they do fail, this is due to some derangement or other. Thus only in a minority of cases do the senses judge inaccurately of their proper objects, and then only through some organic defect, e.g. when people sick with fever taste sweet things as bitter because their tongues are ill-disposed.

             § 662. But the senses have also their indirect objects, and with regard to these they can be deceived. What seems to be white is indeed white as the sense reports; but whether the white thing is this or that thing, is snow, e.g., or flour, is a question often answered badly by the senses, especially at a distance.

             § 663. Thirdly, there are the 'common sensibles', found in things some of whose accidental qualities are 'proper sensibles'. Thus size and movement accompany, as 'common sensibles', the sensible qualities of bodies. And these are very likely to give rise to error; for in their case our judgement has to adjust itself to differences of distance: things seen further away seem the smaller.

             § 664. Now the movement of imagination, being derived from the actuated senses, differs from these three types of actual sensation as an effect from its cause. Thus, just because effects, as such, are weaker than their causes, and the power and impress of an agent is less and less evident the further away are its effects, therefore imagination is even more liable than are the senses to fall into the error which arises from 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 kind, not in point of materiality (for example, if a sweet savour is tasted on the tongue as bitter); for in point of materiality there is always a difference between the form as received in the sense and the form as existing in the object. It follows too, from what we have said, that imagination is generally truthful when it arises from the action of the 'proper sensibles'; I mean, at least so long as the sensible object is present and the image-movement is simultaneous with the sense-movement.

             § 665. But when the image-movement occurs in the absence of the exterior sense-object we can be deceived, even with regard to proper sensibles. We may imagine absent black things as white. On the other hand, the image-movements arising from perception of objects indirectly sensed, or of the common-sensibles, are liable to go astray whether the exterior object be present or no; although they are the more liable to error in the object's absence.

             § 666. From this argument he then draws a conclusion touching his main contention: namely, if the foregoing remarks are true of nothing but the imagination, and are certainly true of it, then imagination must be the movement proceeding from the actuated senses.

             § 667. Whether this movement also presupposes some potency other than the exterior senses, 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 potency distinct from the exterior senses.

             § 668. (b) Next, at 'Since sight', he explains the name phantasia. Note that phos is the Greek for light, whence comes phanos, i.e. 'appearance' or 'enlightening', and phantasia. He says, then, that, because sight is the principal sense, being more spiritual (as we have seen already) and knowing a wider range of objects than any other, therefore imagination, which arises from actual sensation, gets its name from light, without which nothing can be seen.

             § 669. (c) Then, at 'And since these images', he explains why the actions and passions of animals are governed by imagination. Images, he says, 'dwell within' in the absence of sensible objects, as traces of actual sensations; therefore, just as sensations arouse appetitive impulses whilst the sensed objects are present, so do images when these are absent. And therefore images very largely determine the behaviour of animals. Nevertheless, this happens through their lack of intelligence; and where intelligence is present it is able, being a higher faculty, to make its own judgement prevail in practice.

             § 670. Hence, so long as the intellect is not in command animals are swayed by imagination; some animals because they simply lack intelligence (the beasts), and some in so far as their intellect is veiled (men). And men may be so swayed in three ways: (a) when they fall into some passion, such as anger, desire, fear etc.; (b) when they are of unsound mind, through delirium or insanity; and (c) when they are asleep and dreaming. In these cases the intellect ceases to control the imagination, with the result that men take their imaginary representations for the truth.

             In conclusion, he says that he has now stated what the imagination is and whence it arises.

429a 10-429b 4