 Feuerbach made his first attempt to challenge prevailing ways of thinking about individuality in his inaugural dissertation, where he presented himself as a defender of speculative philosophy against those critics who claim that human reason is restricted to certain limits beyond which all inquiry is futile, and who accuse speculative philosophers of having transgressed these. This criticism, he argued, presupposes a conception of reason is a cognitive faculty of the individual thinking subject that is employed as an instrument for apprehending truths. He aimed to show that this view of the nature of reason is mistaken, that reason is one and the same in all thinking subjects, that it is universal and infinite, and that thinking (Denken) is not an activity performed by the individual, but rather by “the species” acting through the individual. “In thinking”, Feuerbach wrote, “I am bound together with, or rather, I am one with—indeed, I myself am—all human beings” (GW I:18).