Good, then, is the sum and source of all desirable things.

That which has not in itself any good, either in reality or in semblance, can in no wise be desired.

Contrariwise, even things which by nature are not good are desired as if they were truly good, if they seem to be so.

Whereby it comes to pass that goodness is rightly believed to be the sum and hinge and cause of all things desirable.

Now, that for the sake of which anything is desired itself seems to be most wished for.