§2.8.1. Do things that are far away appear to be smaller, and do things that are far removed from us seem to be at a short distance from us, while things that are near appear to be as large as they actually are and to have the distance from us that they actually have? Distant things seem smaller to those seeing them because light tends to get contracted to fit5 one’s sight, that is, to fit the magnitude of the pupil.2 Or else3 as the distance between the matter of the object of sight and the pupil is increased, the form arrives as more isolated [from matter], in a way, with even the quantity itself becoming form and quality, so that only its rational content arrives at the pupil. Or else because we perceive a thing’s magnitude through a detailed survey and inspection of how10 large each of its parts is. It must, then, be present and up close in order for it to be known how large it is.
Or else because it is only accidentally that magnitude is seen, since colour is the primary object of vision.4 At close quarters, then, one knows how large of a thing has been coloured, but at a distance one knows that it is coloured, yet the parts, because their largeness has been contracted, do not grant us the means to distinguish accurately how15 large the coloured object is. This is so, since even the colours themselves become dim at a distance. Why is it surprising, then, if things’ magnitudes, too, diminish, just as sounds do, to the extent that their form comes to us in a dim state? For in the case of hearing, too, it is the form that hearing examines, whereas magnitude is perceived only20 accidentally.
On the topic of hearing, however, one might ask whether magnitude is, in fact, perceived accidentally. After all, to what sense other than hearing does auditory magnitude appear as a primary object, just as visible magnitude appears primarily to touch?
In fact, hearing perceives a sound’s apparent magnitude not in terms of how large it is but in terms of degrees of more or less, that is to say, the intensity [of its volume], and this is not accidental, just as it is not accidental that taste, too, perceives the intensity of sweetness. But the25 proper magnitude of a sound is the area it reaches, and this might be indicated accidentally by the intensity [of volume], but not in any accurate way. For each sound has its own intensity that remains identical, but the actual magnitude increases as the sound proceeds to the whole region of its extension. Yet colours become dim with distance, not small; it is magnitudes that become small. What is common in both30 cases is that what they are is diminished, and for a colour diminution, then, means dimness, while for a magnitude it means smallness, and since magnitude accompanies colour,5 the magnitude is diminished proportionately.
And this occurs more clearly in the case of objects of sight variegated in colour, for example, mountains having lots of houses and trees and other things on them, since each of these things, if they35 are seen, gives one the ability to measure the whole on the basis of the individual components of the sight. But if the form of the individual component6 does not reach the eye, then sight, which knows the whole by measuring the underlying magnitude, is deprived of its knowledge of how large the whole is. And even with objects close by, if they are variegated in colour and our apprehension of them takes place quickly and not all of the forms of the40 components are seen, the object would appear smaller in proportion to each component that is hidden from view. But when all of the components are seen, we measure them accurately and know their magnitudes. But those magnitudes that are homogeneous and monochrome deceive us with respect to how large they are, since our sight is not able to measure part by part very well, because when it45 attempts to measure part by part it slips up, since it cannot use the diversity of the individual parts to get a purchase on them.
And objects far away appear close by because the length of the interval separating them from us is shortened for the identical reason. For our sight is not deceived about how large the nearer part of the interval is, and this is for the identical reason. But because our sight does not go out to the far end of the interval, it is not able to declare what kind50 of thing the object is in terms of its form nor how large it is in terms of its magnitude.
§2.8.2. Regarding the claim that this phenomenon is due to the smaller angles of sight,7 it has already been said elsewhere8 that this is not the case, and here we need only say that the one who claims that things appear smaller due to a smaller angle of sight is not taking account of the fact that the rest of one’s sight is seeing something surrounding that object, either some other object of sight or else whatever it is that5 generally surrounds objects, for example, air. When, then, sight leaves nothing out because the mountain [that it is directed at] is big – that is, when sight is rather equal to its object and it is no longer possible for it to see anything else, inasmuch as the interval of the field of sight coincides with that of the object of sight, or also when the object of sight exceeds the field of sight both vertically and horizontally – what would one say in this case, where the underlying [magnitude] of the object of sight appears to be much smaller than it really is and yet it is10 seen by one’s entire sight? Indeed, if one would consider the case of heaven, one would undoubtedly understand. For it is impossible for one to see the entire heavenly hemisphere in one look; not even if sight were to extend as far as heaven would it be able to spread itself out so extensively. But let’s grant this, if someone insists. If our entire field of15 sight, then, were to encompass the entire hemisphere, and if the magnitude of the object of sight in heaven is in reality many times larger than it appears to us – since it appears to be much smaller than it is – then how could the smaller angle of sight be responsible for distant objects appearing smaller?
1 In his VP Porphyry twice gives a slightly different title: How it is That Things Seen at a Distance Appear Small.
2 Cf. 1.6.3.9–15; 4.7.6.19–22.
3 Inserting ἢ καὶ with Theiler.
4 Cf. infra 7.26–27. See Ar., DA 2.6.418a11–13.
5 See Ar., DA 3.1.425b8–9.
6 Reading τοῦ δὲ εἴδους <τοῦ> καθ᾽ ἕκαστον with Theiler and HS3 and ἡ ὄψις with Theiler and HS3 but retaining τοῦ καθ᾽ ἕκαστον of HS2.
7 See Euclid, Opt. Definition 4.2.10–12.
8 Such a passage is not to be found in the Enneads.