The Taoists realized that no single concept or value could be considered absolute or superior. If being useful is beneficial, the being useless is also beneficial. The ease with which such opposites may change places is depicted in a Taoist story about a farmer whose horse ran away.
His neighbor commiserated only to be told, "Who knows what's good or bad?" It was true. The next day the horse returned, bringing with it a drove of wild horses it had befriended in its wanderings. The neighbor came over again, this time to congratulate the farmer on his windfall. He was met with the same observation: "Who knows what is good or bad?" True this time too; the next day the farmer's son tried to mount one of the wild horses and fell off, breaking his leg. Back came the neighbor, this time with more commiserations, only to encounter for the third time the same response, "Who knows what is good or bad?" And once again the farmer's point was well taken, for the following day soldiers came by commandeering for the army and because of his injury, the son was not drafted.
According to the Taoists, yang and yin, light and shadow, useful and useless are all different aspects of the whole, and the minute we choose one side and block out the other, we upset nature's balance. If we are to be whole and follow the way of nature, we must pursue the difficult process of embracing the opposites.