"Kant's 'Ich denke' and the transcendental apperception. Some reflections on thinking and existence"

In his monograph "Das 'Ich denke' und Kants transzendentale Deduktion im Lichte der Sprachphilosophischen (pragmatischen) Wende", Audun Øfsti claims that Kant's theoretical philosophy expresses a methodological solipsism. According to him, Kant's solipsism does not coincide with the Cartesian solipsism which concerns the relation between the subject and the world. Instead, Kant's methodological solipsism does not, according to Øfsti, give an account of the intersubjective relation between the subject and its co-subject(s). Øfsti's conception of Kant's methodological solipsism is based on his interpretation of Kant's expression 'Ich denke' in the paragraph 16 of the transcendental deduction in "Kritik der reinen Vernunft". Here, Øfsti suggests that in order to avoid methodological solipsism, Kant's 'Ich denke' should be interpreted as a "performative" in the Austinian sense. According to Øfsti, a performative analysis of Kant's 'Ich denke'makes it possible to draw a more clear distinction between the deictic and the performative aspects of the subject. This distinction is not shown in Kant's own argumentation in connection with 'Ich denke'. In this paper, I will examine Kant's notion of 'Ich denke', to see if, or to what extent, it has to be considered as an argument which can be said to express a certain kind of methodological solipsism, as Øfsti maintains.