Page - 281 - in The Complete Aristotle

Next, for destructive purposes, see if he has stated a thing as a property of itself: for then what has been stated to be a property will not be a property. For a thing itself always shows its own essence, and what shows the essence is not a property but a definition. Thus (e.g.) he who has said that ‘becoming’ is a property of ‘beautiful’ has rendered the term as a property of itself (for ‘beautiful’ and ‘becoming’ are the same); and so ‘becoming’ could not be a property of ‘beautiful’. For constructive purposes, on the other hand, see if he has avoided rendering a thing as a property of itself, but has yet stated a convertible predicate: for then what is stated not to be a property will be a property. Thus he who has stated ‘animate substance’ as a property of ‘living- creature’ has not stated ‘living-creature’ as a property of itself, but has rendered a convertible predicate, so that ‘animate substance’ would be a property of ‘living-creature’. Next, in the case of things consisting of like parts, you should look and see, for destructive purposes, if the property of the whole be not true of the part, or if that of the part be not predicated of the whole: for then what has been stated to be the property will not be a property. In some cases it happens that this is so: for sometimes in rendering a property in the case of things that consist of like parts a man may have his eye on the whole, while sometimes he may address himself to what is predicated of the part: and then in neither case will it have been rightly rendered. Take an instance referring to the whole: the man who has said that it is a property of the ‘sea’ to be ‘the largest volume of salt water’, has stated the property of something that consists of like parts, but has rendered an attribute of such a kind as is not true of the part (for a particular sea is not ‘the largest volume of salt water’); and so the largest volume of salt water’ could not be a property of the ‘sea’. Now take one referring to the part: the man who has stated that it is a property of ‘air’ to be ‘breathable’ has stated the property of something that consists of like parts, but he has stated an attribute such as, though true of some air, is still not predicable of the whole (for the whole of the air is not breathable); and so ‘breathable’ could not be a property of ‘air’. For constructive purposes, on the other hand, see whether, while it is true of each of the things with similar parts, it is on the other hand a property of them taken as a collective whole: for then what has been stated not to be a property will be a property. Thus (e.g.) while it is true of earth everywhere that it naturally falls downwards, it is a property of the various particular pieces of earth taken as ‘the Earth’, so that it would be a property of ‘earth’ ‘naturally to fall downwards’. < div id=“section47” class=“section” title=“6”> 281