Chinese Philosophy – Gongsun Long
Gongsun Long (325-250 BCE) also appears in the Zhuangzi, where he says:
When I grew up, I understood the practice of kindness and duty. I united the same and different, separated hard from white, made so the not-so and admissible the inadmissible. I confounded the wits of the hundred schools and exhausted the eloquence of countless speakers. I took myself to have reached the ultimate.
Gongsun’s writings are now lost, but his famous ‘A White Horse Is Not A Horse’ argument lives on. Many say that this argument is faulty, but if we follow the thinking of the Daoists and Hui Shi we can see that they are quibbling, and Gongsun is showing us the two types of ‘is’ we saw earlier in Buddhist Logic. Gongsun does not mean that a white horse is not in any way a horse, but that in one particular way “a white horse” is not the same thing as “a horse”. He argues that if one brings a yellow horse, it would not fit the description “a white horse” but it would do fine for the description “a horse”. The two are thus different sets and are not identical though one set is a subset of the other. This means that “a white horse” is and is not “a horse” (in one way “is” and in another way “is not”), and so he can truly say that “a white horse is not a horse”, like Hui Shi saying the parts of the full truth that sound most paradoxical when said side by side.
Consider that your finger is you but also is not you. If we use “is” in terms of strict identity (like Clark Kent is Superman) then your finger is not you because you are much more than a finger. However, if we use “is” to mean a part incorporated within a thing (like a tree is green, or trees are green things) then your finger is you because it is part of you. Bill Clinton famously tried explaining this with his “that depends what your definition of ‘is’ is”, which did not gain him much sympathy. Being an individual human, you are and are not humanity. In fact, you are only one human out of quadrillions so far, so you are not very much of humanity at all, but what are you more than a human?
Gongsun Long’s white horse argument demonstrates something basic in formal logic, that a conditional is not necessarily biconditional. If I know “If A, then B“, I do not know “If B, then A“. If something is part of my finger, then it is part of me, but this does not mean that if something is a part of me, it is a part of my finger (for instance, my ear). If something is a white horse, then it is a horse, but if something is a horse, this does not mean that it is a white horse, as it could be a black or yellow horse.
In searching for images of Gongsun Long online, I found these awesome comics from cowbirdsinlove.com: