 Bruno’s two universal principles resembled Stoic doctrine in another respect. For the Stoics, “first matter” was an unqualified substance (ousia). For Bruno, too, Universal Matter was a substance and in act, not a prope nihil (“almost nothing”) of the kind imagined by Aristotle. The similarities, however, cease at this point. For the Stoics, whatever existed, even soul and matter, was corporeal, capable of acting on or being acted upon by another corporeal entity. By contrast, neither of Bruno’s principles was corporeal. The Universal Soul was an intelligible reality; and Universal Matter was not corporeal in the Stoic sense. Inherently qualityless, dimensionless, impassive and inactive, Universal Matter was a medium that had the potentiality to become all things. To explain why Universal Matter conceived in this manner was a substance, Bruno drew on Thomas Aquinas’s commentary on Aristotle’s reportage of ideas proposed by “ancient philosophers” (Commentary on Aristotle’s Physics, II, lectio 2, §1). Wood was a substance in act because it was that from which a bed, stool or image could be made, not because it was any one of those things; and the same was true of Universal Matter. It was not so much the effects elicited from Universal Matter by the Universal Soul’s faculty, the Universal Intellect, which were in act, but rather Universal Matter itself. It was in act by virtue of the unexplicated forms that the Universal Intellect could incite from within it, not by virtue of the explicated material forms that it produced. Nicholas of Cusa supplied the language of explication and implication.