from I Kant:
- The principle of contradiction and of Identity (principium contradictionis and identitatis) by which the intrinsic possibility of a cognition is determined for problematical judgments.
- The principle of sufficient reason (principium rationis sufficientis) on which the (logical) actuality of a cognition depends; that it is well-founded, as material for assertorial judgments.
- The principle of excluded middles (principium exclusi medii inter duo contradictoria) on which the (logical) necessity of a cognition is based, that we must necessarily judge thus and not otherwise, that is, the contradictory is false. This is the principle of apodictic judgments.