"[L]et us consider, with respect to causes, what they are, and how many there are in number... this also must be done by us in discoursing concerning generation and corruption, and all physical mutation... knowing the principles of these... Cause... is after one manner said to be that, from which, being inherent, something is produced... But after another manner cause is form and paradigm (and this is the definition of the essence of a thing) and the genera of this. ...But it happens... that there are also many causes of the same thing, and this is not from accident. ...seed, a physician, he who consults, and, in short, he who makes, are all of them causes, as that whence the principle of mutation, or permanency, or motion is derived. ...It is, however, necessary always to investigate the supreme cause of every thing ...Further still, it is necessary to investigate the genera of genera; and the particulars of particulars... We should also explore the capacities of the capabilities, and the energizers of the things affected by energy."