Full Idea
I concluded that I was a substance, of which the whole essence or nature consists in thinking, and which, in order to exist, needs no place and depends on no material thing.
Gist of Idea
I am a thinking substance, which doesn't need a place or material support
Source
René Descartes (A Discourse on Method [1637], §4.33)
Book Reference
Descartes,René: 'Discourse on Method/The Meditations', ed/tr. Sutcliffe,F.E. [Penguin 1968], p.54
A Reaction
To me that sounds like "I concluded that I wasn't a human being", which highlights the bizarre wishful thinking that seems to have gripped the human race for the first few thousand years of its serious thinking.
Related Idea
Idea 18462 The soul is everywhere and nowhere in the body, and must be its cause [Porphyry]