This also necessitated a rejection of the Cartesian, disembodied Cogito: that is, an 'I' as a purely thinking object. 代之，海德格堅持，任何人類行為嘅分析都應由「我哋係喺世界入面」呢一事實開始 (not viewing it in an 'abstract' fashion): therefore the fundamental fact about human existence is our 'being-in-the-world'. Human beings, or Dasein (German"" da—there/here; sein—being or its; dasein—existence), Heidegger insisted, are embodied beings who act in the world. He therefore rejected the 'subject-object' distinction assumed by most philosophers since Descartes and so rejected terms like Consciousness, ego, human being, Man, which are so laden with Cartesian dualism that, for his purposes, they are practically useless. Instead he uses the German portmanteau, Dasein.