Physics

For we say that one thing comes to be from another, and another from another, speaking either of the simple things or of the composite ones. I mean this in the following way: it is possible for a man to become musical, and it is possible for the non-musical to become musical, or for the non-musical man to become a musical man. I call that which comes to be simple, for instance, the man and the non-musical, and that which results simple, the musical; but I call it composite when we say that the non-musical man becomes a musical man. Of these, one is said to become this not only from this, for example, musical from non-musical, but this is not said of everything; for a musical person did not come from a man, but a man became musical. Of the things that come to be, as we say they come to be simply, one remains and comes to be, while the other does not remain; for the man remains becoming musical and is a man, but the non-musical and the unmusical do not remain, neither simply nor as part of a composite. These things being defined, one can take this from all things that come to be, if one looks at it, as we say, that there must always be something underlying that which comes to be, and this, even if it is one in number, is not one in form; for I mean by form and by definition the same thing; for being a man is not the same as being unmusical. And one thing remains, the other does not; the non-opposite remains (for the man remains), but the musical and the unmusical do not remain, nor does the composite of both, such as a musical man. The phrase "something comes to be from something" is used more for things that do not remain, for example, musical comes to be from unmusical, but not from man. Nevertheless, it is sometimes said in the same way for those that do remain; for we say a statue comes to be from bronze, not the bronze becomes a statue.