Free The Life of the Mind by Hannah Arendt

One has been the most outstanding feature of the philosopher's life ever since Parmenides and Plato discovered that for those "very few," the
sophoi,
the "life of thinking" that knows neither joy nor grief is the most divine of all, and
nous,
thought itself, is "the king of heaven and earth." 55
    Descartes, true to the radical subjectivism that was the philosophers' first reaction to the new glories of science, no longer ascribed the gratifications of this way of life to the objects of thinking—the everlastingness of the
kosmos
that neither comes into being nor ever vanishes from it and thus gives those few who have decided to spend their lives as its spectators their share of immortality. His very modern suspicion of man's cognitive and sensory apparatus made him define with greater clarity than anyone before him as properties of the
res cogitans
certain characteristics that were by no means unknown to the ancients but that now, perhaps for the first time, assumed a paramount importance. Outstanding among these was self-sufficiency, namely, that this ego has "no need of any place, nor does it depend on any material thing," and, next, worldlessness, namely, that in self-inspection, "
examinant avec attention ce que j'étais,
" he could easily "
feindre que je n'avais aucun corps et qu'il n'y avait aucun monde ni aucun lieu où je fusse
" ( "feign that I had no body, and that there was no world nor place where I would be" ). 56
    To be sure, none of these discoveries, or, rather, re-discoveries, was of great importance in itself to Descartes. His main concern was to find something—the thinking ego or, in his words, "
la chose pensante,
" which he equated with the soul—whose reality was beyond suspicion, beyond the illusions of sense perception: even the power of an all-powerful
Dieu trompeur
would not be able to shatter the certainty of a consciousness that had withdrawn from all sense experience. Although everything given may be illusion and dream, the dreamer, if he will only consent not to demand reality of the dream, must be real. Hence, "
Je pense, donc je suis,
" "I think, therefore I am." So strong was the experience of the thinking activity itself, on the one hand, so passionate on the other the desire to find certainty and some sort of abiding permanence after the new science had discovered "
la terre mouvantet
" (the shifting quicksand of the very ground on which we stand), that it never occurred to him that no
cogitatio
and no
cogito me cogitare,
no consciousness of an acting self that had suspended all faith in the reality of its intentional objects, would ever have been able to convince him of his own reality had he actually been bom in a desert, without a body and its senses to perceive "material" things and without fellow-creatures to assure him that what he perceived was perceived by them too. The Cartesian
res cogitans,
this fictitious creature, bodiless, senseless, and forsaken, would not even know that there is such a thing as reality and a possible distinction between the real and the unreal, between the common world of waking life and the private non-world of our dreams. What Merleau-Ponty had to say against Descartes is brilliantly right: To reduce perception to the thought of perceiving ... is to take out an insurance against doubt whose premiums are more onerous than the loss for which it is to indemnify us: for it is to ... move to a type of certitude that will never restore to us the 'there is' of the world." 57
    Moreover, it is precisely the thinking activity—the experiences of the thinking ego—that gives rise to doubt of the world's reality and of my own. Thinking can seize upon and get hold of everything real—event, object, its own thoughts; their realness is the only property that remains stubbornly beyond its reach. The
cogito ergo sum
is a fallacy not only in the sense that, as Nietzsche remarked, from the
cogito
only the existence of
cogitationes
could be