@guigus,
Decartes did not doubt everything. He retained a major tacit presupposition of his culture: i.e., that there is a SELF or agent of thought, perception and action, that self who, because HE (the self) thought, ergo necessarily exists (cogito ergo sum). Actually he only saw--in the sense of radical empiricism--thinking, not a self who was thinking. He THOUGHT there was a self/agent/ or subject of thought.
When I look I see thinking, seeing, therefore there is only thinking or seeing, not an agent of thought and perception--despite the fact that my grammar compels me to say to you here that "When 'I" look....
I AM experience, not the recepient of experience.