Full Idea
The consciousness that says 'I think' is precisely not the consciousness that thinks.
Gist of Idea
The consciousness that says 'I think' is not the consciousness that thinks
Source
Jean-Paul Sartre (Transcendence of the Ego [1937], I (B))
Book Reference
Sartre,Jean-Paul: 'The Transcendence of the Ego' [Routledge 2004], p.10
A Reaction
All parties seem to be agreed that if we are going to introspect in search of our own ego, we must distinguish between the mental act of instrospection and the mental act of applying the mind to the world. Each gives a different result.