Plato thus defines a voice,--that it is a breath drawn by the mind through the mouth, and a blow impressed on the air and through the ear, brain, and blood transmitted to the soul. Voice is abusively attributed to irrational and inanimate beings; thus we improperly call the neighing of horses or any other sound by the name of voice. But properly a voice [Greek omitted] is an articulate sound, which illustrates [Greek omitted] the understanding of man. Epicurus says that it is an efflux emitted from things that are vocal, or that give sounds or great noises; this is broken into those fragments which are after the same configuration. Like figures are round figures with round, and irregular and triangular with those of the same kind. These falling upon the ears produce the sense of hearing. This is seen in leaking vessels, and in fullers when they fan or blow their cloths. Democritus, that the air is broken into bodies of similar configuration, and these are rolled up and down with the fragments of the voice; as it is proverbially said, One daw lights with another, or, God always brings like to like. Thus we see upon the seashore, that stones like to one another are found in the same place, in one place the long-shaped, in another the round are seen. So in sieves, things of the same form meet together, but those that are different are divided; as pulse and beans falling from the same sieve are separated one from another. To this it may be objected: How can some fragments of air fill a theatre in which there is an infinite company of persons. The Stoics, that the air is not composed of small fragments, but is a continued body and nowhere admits a vacuum; and being struck with the air, it is infinitely moved in waves and in right circles, until it fill that air which surrounds it; as we see in a fish-pool which we smite by a falling stone cast upon it; yet the air is moved spherically, the water orbicularly. Anaxagoras says a voice is then formed when upon a solid air the breath is incident, which being repercussed is carried to the ears; after the same manner the echo is produced. CHAPTER XX. WHETHER THE VOICE IS INCORPOREAL. WHAT IS IT THAT THE GIVES ECHO?