[German Version]
I. The distinction between a priori ("from the former") and a posteriori ("from the latter") is used by philosophy on various levels.
1. Fundamental is the epistemological distinction between two kinds of epistemic (i.e. cognitive) justifications (e.g. grounds or proofs). A justification is a priori if it is not based on experience; otherwise it is a posteriori. The result is an important distinction between two kinds of knowledge: a true conviction involves a priori knowledge when it can be justified a priori (i.e., independent of experience), otherwise a posterior…