"Any decent philosophical problem is held in place not by one mistake or confusion but by a whole range. Wittgenstein has a wonderful metaphor: if you shine strong light on one side of a problem, it casts long shadows on the other. Every deep philosophical confusion is held in place by numerous struts, and one cannot demolish the confusion merely by knocking one strut away. One has to circle around the problem again and again to illuminate all the misconceptions that hold it in place."
--P.M.S. Hacker, quoted in The Philosophers' Magazine