apparatus and method - that is, follow the examples set by geometry and the physical sciences and let metaphysics be guided by purely rational principles.So by using the subject as an epistemological standard certain knowledge became a purely formal affair. According to Kant, the truth value and validity of a judgment is a function of the subjective position of the observer (subject) rather than a function of the qualities of the observed object in its truly scientific form -das Ding an sich- which, however, is epistemologically inaccessible and belongs to an aspect of reality placed beyond the epistemological subject.114 Hence, the truly objective, scientific form of the object can only be determined indirectly, via a rational reconstruction of the object, but not via direct observation.Accordingly, the truth value of the synthetic a priori is a function of the inner faculties of the observer’s mind, implying that the synthetic a priori only derives its apodictic certainty from the subject side, the formal side of the epistemological relation rather than from the inner qualities of the observed object. For according to theory it is only the fundamental laws of thought that allow the subject to reconstruct das Ding an sich rationally, in order to determine the synthetic judgment a priori. By letting the subject provide the conditions determining the validity of synthetic judgments a priori the synthetic judgment a priori no longer must derive its “apodictic” certainty from the mere appearance of objectivity of the phenomenon rather than the substantive objectivity of the noumenon. As will be shown, Hägerström’s critique amounts to this simple observation: if only the phenomenoncould supply the material for a proper synthetic judgment, then synthetic judgments can never constitute judgments a priori proper, hence synthetic judgments are judgments valid a posteriori, because, in order for the scientific judgment to be apodictically and unconditionally certain, the p a r t i 1 , c h a p t e r 2 70 114 Cf. ibid.