 Wittgenstein points out in the diary case ‘I first want to observe that a definition of the sign cannot be formulated’. (The translation here obscures the reason why. Wittgenstein’s word is ‘aussprechen’, better translated as ‘expressed’ than ‘formulated’: the point follows by definition from the fact that the case is one where the definition is private.) So if meaning is to be obtained for the “sign”, this must be achieved through a private exercise of ostensive definition, where I concentrate on the sensation and produce the sign at the same time. (In these circumstances, meaning cannot be extracted from a pre-existing practice of private use, since what is in question is how such a use could be established in the first place.) But if this exercise is to be genuine and successful ostensive definition, it must establish the connection between sign and sensation, and this connection must persist. As Wittgenstein says, ‘“I commit [the connection] to memory” can only mean: this process brings it about that I remember the connection correctly in the future’. For I do not define anything, even to myself let alone anyone else, by merely attending to something and making a mark, unless this episode has the appropriate consequences.