Plotinus

“ Now consider some very large object of vision, that mountain for example. No part of the eye is unoccupied; the mountain adequately fills it so that it can take in nothing beyond, for the mountain as seen either corresponds exactly to the eye-space or stretches away out of range to right and to left. How does the explanation by lesser angle of vision hold good in this case, where the object still appears smaller, far, than it is and yet occupies the eye entire? ”

“ Take mountains dotted with houses, woods and other land-marks; the observation of each detail gives us the means of calculating, by the single objects noted, the total extent covered: but, where no such detail of form reaches us, our vision, which deals with detail, has not the means towards the knowledge of the whole by measurement of any one clearly discerned magnitude. ”

“ The magnitude of a sound is known not by actual quantity but by degree of impact, by intensity- and this in no indirect knowledge; the ear appreciates a certain degree of force, exactly as the palate perceives by no indirect knowledge, a certain degree of sweetness. But the true magnitude of a sound is its extension ”