Did Descartes here infer more than he was entitled to? As many commentators have pointed out (beginning with Georg Lichtenberg in the eighteenth century), the “I” in his ultimate premise is not quite legitimate. All Descartes could assert with certainty was “There are thoughts.” He never proved that thoughts require a thinker. Perhaps the pronoun “I” in his proof was just a misleading artifact of grammar, not a name for a genuinely existing thing.
