Book 9
11.84
The sixth mode relates to mixtures and participations, by virtue of which nothing appears pure in and by itself, but only in combination with air, light, moisture, solidity, heat, cold, movement, exhalations and other forces. For purple shows different tints in sunlight, moonlight, and lamplight; and our own complexion does not appear the same at noon and when the sun is low.
11.85
Again, a rock which in air takes two men to lift is easily moved about in water, either because, being in reality heavy, it is lifted by the water or because, being light, it is made heavy by the air. Of its own inherent property we know nothing, any more than of the constituent oils in an ointment.
11.85
The seventh mode has reference to distances, positions, places and the occupants of the places. In this mode things which are thought to be large appear small, square things round; flat things appear to have projections, straight things to be bent, and colourless coloured. So the sun, on account of its distance, appears small, mountains when far away appear misty and smooth, but when near at hand rugged.
11.86
Furthermore, the sun at its rising has a certain appearance, but has a dissimilar appearance when in mid-heaven, and the same body one appearance in a wood and another in open country. The image again varies according to the position of the object, and a dove’s neck according to the way it is turned. Since, then, it is not possible to observe these things apart from places and positions, their real nature is unknowable.
11.86
The eighth mode is concerned with quantities and qualities of things, say heat or cold, swiftness or slowness, colourlessness or variety of colours. Thus wine taken in moderation strengthens the body, but too much of it is weakening; and so with food and other things.
