Floating man experiential field shows that the self is not consequently a substance and thereby there is no subjectivity. On the other hand some scholars like Wisnovsky believe that the flying man argument proved the substantiality of the soul. Ibn Sina believes that innate awareness is completely independent of sensory experience. Before the French philosopher Descartes (1596–1650) pointed out the existence of the conscious self as a turning point in epistemology, using the phrase "Cogito ergo sum," the 11th century Iranian philosopher Avicenna had referred to the existence of consciousness in the flying man argument. Thus, long before Descartes, Avicenna had established
Cogito, ergo sum and that "I" know what "thinking" is. He suggested a more appropriate phrase would be "it thinks" wherein the "it" could be an impersonal subject as in the sentence "It is raining." The Danish philosopher Søren Kierkegaard calls the phrase a tautology in his "Concluding Unscientific Postscript". He argues that the "cogito" already presupposes the existence of "I", and therefore concluding with existence is logically trivial. Kierkegaard's argument can be made clearer if one extracts the premise "I think" into the premises "'x' thinks" and "I am that 'x'", where "x" is used as a placeholder in order to disambiguate