I have added an essay on Aristotle’s search for the causes of being. Aristotle conducted a scientific search for the cause(s) of being. He ifdentified four main causes of material beings: final (the extrinsic purpose), formal (the internal form), efficient (the extrinsic agent that actualizes the possibility of the thing – if the thing could realize itself it would never remain a possibility) and material causes (the intrinsic passive, determinable principle, the principle of limitation without which the form could not be realized. The breakthrough key to Aristotle’s search was one of the modes of being called substance, which is an all beings that exist in their own right (ex. man) as opposed to depending on a substance for their being (man’s color is an accidental mode of being).