Theophr. _de sens._ 7; _Dox._ 500. Empedokles speaks in like manner concerning all the senses, and says that we perceive by a fitting into the pores of each sense. So they are not able to discern one another’s objects, for the pores of some are too wide and of others too narrow for the object of sensation, so that some things go right through untouched, and others are unable to enter completely. And he attempts to describe what vision is; and he says that what is in the eye is fire and water, and what surrounds it is earth and air, through which light being fine enters, as the light in lanterns. Pores of fire and water are set alternately, and the fire-pores recognise white objects, the water-pores black objects; for the colours harmonise with the pores. And the colours move into vision by means of effluences. And they are not composed alike ... and some of opposite elements; for some the fire is within and for others it is on the outside, so some animals see better in the daytime and others at night; those that have less fire see better by day, for the light inside them is balanced by the light outside them; and those that have less water see better at night, for what is lacking is made up for them. And in the opposite case the contrary is true; for those that have the more fire are dim-sighted, since the fire increasing plasters up and covers the pores of water in the daytime; and for those that have water in excess, the same thing happens at night; for the fire is covered up by the water.... Until in the case of some the water is separated by the outside light, and in the case of others the fire by the air; for the cure of each is its opposite. That which is composed of both in equal parts is the best tempered and most excellent vision. This, approximately, is what he says concerning vision. And hearing is the result of noises coming from outside. For when (the air) is set in motion by a sound, there is an echo within; for the hearing is as it were a bell echoing within, and the ear he calls an ‘offshoot of flesh’ (v. 315): and the air when it is set in motion strikes on something hard and makes an echo.[86] And smell is connected with breathing, so those have the keenest smell whose breath moves most quickly; and the strongest odour arises as an effluence from fine and light bodies. But he makes no careful discrimination with reference to taste and touch separately, either how or by what means they take place, except the general statement that sensation takes place by a fitting into the pores; and pleasure is due to likenesses in the elements and in their mixture, and pain to the opposite. And he speaks similarly concerning thought and ignorance: Thinking is by what is like, and not perceiving is by what is unlike, since thought is the same thing as, or something like, sensation. For recounting how we recognise each thing by each, he said at length (vv. 336-337): Now out of these (elements) all things