Full Idea
The 'I thinks' must be able to accompany all my representations; for otherwise something would be represented in me that could not be thought at all, which is as much as to say that representation would be impossible, or would be nothing to me.
Gist of Idea
Representation would be impossible without the 'I think' that accompanies it
Source
Immanuel Kant (Critique of Pure Reason [1781], B132)
Book Reference
Kant,Immanuel: 'Critique of Pure Reason', ed/tr. Guyer,P /Wood,A W [CUO 1998], p.246
A Reaction
This is evidently a flat rejection of Hume's claim that he is a bundle of experiences with no self to co-ordinate them. Presumably this should apply to animals too, if they 'represent' their world (and how could they not?).