Full Idea
Heidegger argues that having thoughts and feelings is only possible for entity that is actually engaged in the world.
Gist of Idea
Having thoughts and feelings need engagement in the world
Source
report of Martin Heidegger (Being and Time [1927]) by Mark Wrathall - Heidegger: how to read 1
Book Reference
Wrathall,Mark: 'Heidegger: how to read' [Granta 2005], p.10
A Reaction
This seems to be an a priori exclusion of the possibility of a brain in a vat. I guess the ancestor of this idea is Schopenhauer.