 This argument is fairly clearly not about part-whole relations, nor about separating hard from white. The sophist plainly construes “white horse is horse” as “white horse is identical to horse.” In Chinese as in English, the sentence ‘White horses are horses’ can be interpreted as predicating ‘horse’ of white horses, making the true claim that the things picked out by ‘white horse’ are all among those picked out by ‘horse’, or it can be interpreted as expressing an identity, making the false claim that exactly the same things are picked out by ‘white horse’ as by ‘horse’. The argument trades on this ambiguity. Because we know that modifying a noun narrows the scope of its extension, when we hear “white horses are horses,” we naturally apply the principle of charity, assume the speaker is not saying something obviously false, and take the relation in question to be predication, not identity. But the sophist insists on interpreting the sentence as an identity. Notice that the sophist implicitly applies a principle roughly like Leibniz’s law of indiscernibility of identicals. He assumes that if two things are identical, they will share all their features, and one can be substituted for the other in any context. Since what can be “delivered” in answer to a request for “white horse” is different from what can be “delivered” for “horse,” white horse is not  horse.[21]