Plato quotes - page 8
So when the universe was quickened with soul, God was well pleased; and he bethought him to make it yet more like its type. And whereas the type is eternal and nought that is created can be eternal, he devised for it a moving image of abiding eternity, which we call time. And he made days and months and years, which are portions of time; and past and future are forms of time, though we wrongly attribute them also to eternity. For of eternal Being we ought not to say 'it was', 'it shall be', but 'it is' alone: and in like manner we are wrong in saying 'it is' of sensible things which become and perish; for these are ever fleeting and changing, having their existence in time.
Plato
Any one who has common sense will remember that the bewilderments of the eyes are of two kinds, and arise from two causes, either from coming out of the light or from going into the light, which is true of the mind's eye, quite as much as of the bodily eye; and he who remembers this when he sees any one whose vision is perplexed and weak, will not be too ready to laugh; he will first ask whether that soul of man has come out of the brighter light, and is unable to see because unaccustomed to the dark, or having turned from darkness to the day is dazzled by excess of light.
Plato