The seeing of what he calls “aspects”, or the “seeing of something as something”, preoccupied Wittgenstein during the last two decades of his life, and arguably earlier than that. His later manuscripts and typescripts are filled with hundreds of remarks on this subject.

With a few exceptions (cf. PI §§534–9), Wittgenstein never came to incorporate his remarks on aspects, or some selection of them, into what we now have as the first part of the Philosophical Investigations. Nor did he ever come to organize these remarks, or some selection of them, in some other way into a philosophical whole. This is important to keep in mind. While the remarks that make up what we now know as the first part of the Investigations were carefully and deliberately designed, over many years, to make their reader work, the numerous remarks on aspect perception show us Wittgenstein himself at work – making his way in a conceptual landscape that he himself found hard to find his way in. Witness here his saying to Maurice Drury, not long before his death, and after many years of thinking about aspect perception: “Now try and say what is involved in seeing something as something; it is not easy. These thoughts I am now having are as hard as granite” (quoted in Monk 1990: 537). Part of what concerns me in this chapter is the nature of the difficulty Wittgenstein found himself facing in thinking about aspects.