RB 65

The success of Hägerström’s anti-subjectivistic program required that it turned tables on subjectivism, demonstrating that “Cogito ergo sum” could not constitute any secure foundation for objectrelated knowledge.169 In reality, the Cogito-proposition demonstrates that there exists a thinking object, the subject, but the Cogito never proves that being and thinking are inseparable correlatives (which is a central supposition of Cartesian philosophy). According to Hägerström, one forceful objection against the Cogito is that it is possible to negate the Cogito by showing that thinking is one of many possible predicates of an existing thing, but that this predicate alone cannot demonstrate that subjective existence necessarily follows from thinking.170 One could just as well claim that subjective existence follows from spatial extension. Hence, ontological existence does not depend upon the subject’s mental activity; on the contrary, the subject’s mental activity depends upon existence, because it is neither self-evident nor clear and distinct that existing things necessarily think, while on the other hand it is necessary that the thinking objects exist. All that is proved by the Cogito is the individual’s subjective certainty that he himself exists.To any external observer attempting to determine whether or not the (thinking) person exists, the observed person’s mental activities are irrelevant, as well as inaccessible to the observer, and thus of no value as evidence. If compared, the difference between Descartes’ and Hägerström’s philosophies is that while Descartes’ philosophy holds thinking to be logically prior, both in the epistemological and ontological sense, Hägerström’s philosophy holds existence (objective reality) to be logically prior. It was this difference between the basic outlines of Descartes’ and Hägerström’s philosophies that led Hägerström to the conclusion that lack of existence, objective reality, made every other determination philosophically wanton. a ca l l f o r s c i e n t i f i c p u r i t y 87 169 Cf. Hägerström’s Copernican revolution, see chapter 2 above. 170 Fries, Verklighetsbegreppet, pp. 329-330.