I objectively confront every object. But not the I.
So there really is a sense in which there can and must be mention o f the I in a
non-psychological sense in philosophy. [Cf. TLP 5.641] {NB 11.8.16)
As a result, the various methods we use for individuating (simple and complex) objects cannot be applied to the philosophical subject. Our approach to this subject needs to be radically different from our approach to objects. Our traditional methods for individuating things must be put aside if we are to gain a genuine non-psychological insight into the self as a subject.
The subject is not an object, let alone a complex one that could be represented in language. As a result, anything we say about it will, at best, be nonsensical in the first sense. In other words.
statements about the first-personal subject will, at best, be analogous to the nonsensical elucidations that make up the Tractatus (TLP 6.54); they will mistakenly attempt to put into words insights which are correct but unsayable. In addition, a statement about the subject will be nonsensical in sense 2 if it mistakenly attempts to put into words an unsayably incorrect insight about the subject. Hence, the acceptable way for philosophy to talk about the first-personal subject must be, according to Wittgenstein, for it to use statements which are nonsensical in sense 1, but not in sense 2.
To sum up: although the third-personal, psychological notion of the mind has a clear use in language, Wittgenstein argues that it is of little interest to philosophy, in that it fails to capture something crucially important to us. What is of real interest to philosophy is the ‘deeply mysterious’
{NB 5.8.16) notion of the non-thing-like, first-personal subject of experience.
3.2
The doctrine of solipsism
The time has come to show why Wittgenstein might have thought that the insight ‘the world is my world’ is contained within the solipsist’s doctrine. I will therefore draw an outline of the version of solipsism that I take Wittgenstein to have in mind, and will then explain why we should take this to be the type of solipsism that the Tractatus takes as its target. The solipsist envisaged by Wittgenstein puts forward an argument along the following lines:
(A) We can only gain knowledge the world (i.e. of ‘the world as the totality of facts’, in Wittgenstein’s terminology) by experiencing it.
(B) It is impossible to experience that which cannot be experienced (i.e. that which it is impossible to experience).
Hence:
(C) There is no good reason to suppose that anything which cannot be experienced could possibly exist. Having a good reason to suppose this would involve being able to experience that which cannot be experienced, which is impossible.
(D) It is impossible to experience other people’s selves, and
(E) The only self that I do experience is my own. Hence
exist. Again, having a good reason to suppose this would involve being able to experience that which cannot be experienced, which is impossible.
Hence
(G) Only one subject of experience exists and could possibly exist: my self.
(H) Only my self and those things that I can possibly experience exist and could possibly exist.
(I) Conclusion (‘what the solipsist means’, according to Wittgenstein): ‘The world is my world’, everything possible can possibly be experienced by me, there are no possibilities which cannot be experienced by me.
Premises (A) to (H) capture what a solipsist of this type might generally be taken to say. The conclusion (I) presents ‘what the solipsist means', according to Wittgenstein. In other words, it presents what Wittgenstein takes the ultimate conclusion of solipsism to be. And it is clear that (I) can be deduced from the previous premises (i.e. from what a solipsist of this type might generally be taken to say). Let us now consider why this brand of solipsism can be regarded as the one envisaged by Wittgenstein.
3.2.1 A solipsism b a sed on the notion of ex perience
The first thing to note about the argument I have just sketched is that it focuses on the notion of
experience. This isn’t always the case: some versions of solipsism work on the narrower concept
of perception. In contrast, ‘experience’ includes, in Wittgenstein’s terminology, not just perceptions, but also beliefs, and thoughts (see Part VI). This version of solipsism well fits Wittgenstein’s discussion, since TLP 5.634 refers explicitly to this wider concept of experience, and since the eye metaphor (TLP 5.633 and 5.6331) also refers to it implicitly. We therefore have strong reasons to believe that the variety of solipsism which interested Wittgenstein was based on this wider concept of experience, rather than on the narrower one of perception.
The argument sketched above could be amended so as to transform it into an argument for sense-data solipsism. This would be done by replacing the wider notion of experience with the narrower one of perception, and by characterising all perception as being made up of intrinsically private sense-data. Such a solipsist would modify premise (B) by saying that the reason why it is impossible to perceive that which cannot be perceived is that my perceptions form an impenetrable veil of essentially private sense-data standing between me and the supposedly real world. Thus,
his conclusion (I) would become: everything possible can possibly be perceived (in this strongly private sense) by me.
The reason why I haven’t presented the solipsist’s argument in this way is that sense-data solipsism, like sense-data phenomenalism, turns primarily on a particular conception of perception: to perceive is to access directly one’s strongly private sense-data which form an impenetrable veil between us and the supposed real world. In contrast, Wittgenstein’s discussion focuses almost exclusively on the solipsist’s notion of the subject. Indeed, the only way in which experience and perception are explicitly qualified in these entries is when it is said that no part of them can be a
priori {TLP 5.634). There is, therefore, no reason to focus exclusively on this version of the
solipsist’s doctrine. Although Wittgenstein’s argument will have an impact on sense-data solipsism, its impact will not be restricted to it.
3.2.2 A solipsism b ase d on the notion of the possibie
The second thing to note is that this version of the solipsist’s argument puts the emphasis on the notion of what it is possible to experience. Indeed, as noted by Pears, the ‘world’ introduced at
TLP 5.6 is the world of all possible states (TIP 5.6). That this is the notion of the world intended here is shown by the fact that TLP 5.61 (which, according to Wittgenstein’s numbering system, is a comment on TLP 5.6) explicitly mentions the issue of possibilities and the idea of what can and cannot possibly be thought and said:
Logic pervades the world: the limits of the world are also its limits.
So we cannot say in logic, ‘ The w o rld h as this in it, a n d this, b u t n o t that. ’
For that would appear to presuppose that we were excluding certain possibilities,
and this cannot be the case, since it would require that logic should go beyond the limits of the world; for only in that way could it view those limits from the other side as well. (TLP 5.61) [My italics]
We will examine this entry in more detail below.
The ‘world of the solipsist’ is therefore the world as it can possibly be experienced by me, rather than ‘the world as I [actually] found it’ {TLP 5.631), as Pears argues. Indeed, as noted above, starting off with the latter notion renders the interpretation of TLP 5.6 problematic, since it is clear that the world of the possible need not coincide with the world as it has actually been given to me in experience. There is, indeed, no compelling reason to accept Pears’ view that Wittgenstein is in TLP 5.631 defining the variety of solipsism he will be focusing on.
If I wrote a book called The w o rld a s 1 f o u n d i t, I should have to include a report on