  The breakthrough that Eckhart attains through his theory of univocal causality is exemplified by the relation between thinking and thought. For Eckhart, thinking presupposes no origin because a presupposed origin could only be thought by thinking and hence would be a thought of thinking, that is, itself thinking. Thinking is, then, for itself a presuppositionless origin, that is, it is its own principle: principium (Echardus, In Ioh. n. 38; LW III, 32, 11: “… ipsum principium semper est intellectus purus …”: “The principle itself is always pure intellect …”). Any thinking without act, however, is no thinking at all. Consequently, its own originative activity accrues to thinking, that is, insofar as it is a principle, the dynamics of its principiating: principiare.  In this activity, however, thinking directs itself towards a thought that it has originated, that is, towards the product that is its principiate: principiatum. But since this thought is a thought of thinking, it is itself nothing other than thinking. The act of this thinking that has been thought is, then, retrograde. This thought, as thinking, is in turn principle, principiating and principiate, whereby this last is the original thinking. In this way, thinking thinks itself as thought and is therewith active thinking, while thought, insofar as it thinks its thinking, is itself thinking, and its thinking now thought. Consequently, both thinking and thought are at the same time active and passive.