As regards the allegory, it is clear that Tripitaka stands for the ordinary man, blundering anxiously through the difficulties of life, while Monkey stands for the restless instability of genius. Pigsy, again, obviously symbolizes the physical appetites, brute strength, and a kind of cumbrous patience. Sandy is more mysterious. The commentators say that he represents , which is usually translated 'sincerity', but means something more like 'whole-heartedness'.
Wu Cheng'en