 Are the powers themselves particulars or universals? It can be argued that Dharmakīrti and his fellow Buddhists are best understood as trope theorists: the powers/properties that make up particulars are themselves particular entities, differing according to each location in space and time (see  section 2.2.2).  Charles Goodman and others have made a persuasive case that properties (dharma) for Ābhidharmika Buddhists are indeed tropes, i.e., properties that are particular—a blueness, a heat, or a hardness specific to one place-time and not common to several. The Epistemologists’ version of dharmas would be no exception in that respect of being particulars rather than  universals.[20]  The causal theory, however, does make for some significant differences from Ābhidharmikas. Many important Ābhidharmikas, i.e., those of the Sarvāstivāda school, regarded dharmas from a complex double perspective: a) their intrinsic natures (svabhāva), i.e., what they are, and b) their present causal activity (kāritra) along with their capabilities (sāmarthya) to lead to effects when the appropriate circumstances obtain. The intrinsic natures of dharmas are given in terms of categorical properties—being blue, being square, being hard, etc—and are treated like quiddities, what dharmas simply are in themselves. The activities and capabilities, on the other hand, are presented in causal terms, e.g., giving rise to perceptions of blue and square, producing subsequent similar things, etc. Not surprisingly, there are involved Abhidharma debates on the relationship between the intrinsic natures and causal activities/capabilities, a rather typically evasive Sarvāstivādin response (i.e., that of Saṅghabhadra) being that they are neither the same nor  different.[21]  The most radical way out of this problem of the relationship between the intrinsic and the causal is to say, as do Nāgārjuna and his Mādhyamika followers, that there cannot really be any intrinsic natures at all: if anything had a quiddity intrinsically, as Ābhidharmikas and others hold, it would absurdly need to have it completely acausally—nothing could ever cause a thing to be what it is intrinsically. A less radical strategy is a causal theory that makes no separation at all between what something is and what it does. That is the strategy that Dharmakīrti ably  pursued.[22]