In a joint book, entitled Investigating Wittgenstein (Basil Blackwell, Oxford, 1986), we have presented an overall interpretation of the development of Wittgenstein's philosophy and of its several stages. In this paper, we shall show that our interpretation is strongly supported by what Wittgenstein says of one particular problem, the problem of seeing as. This problem is seen in its clearest form in ambiguous figures like the Necker Cube. (See the figure in section 2 below.) This line drawing can be seen as a representation of a cube with two different orientations. You can see either aaaa or bbbb as the front. Why this perceptual ambiguity should present a problem for Wittgenstein or possess other kinds of philosophical relevance for him is far from clear, and remains to be investigated. In fact, the attention paid by Wittgenstein to the phenomenon of seeing as may prima facie seem excessive.