 It is useful to think of a universal in this sense as a non-particular individual (Chakrabarti, 1995). Examples abound: Dusky is what many particulars are, though they may be spatiotemporally separated by many miles and years; rainy is what several days of the year can be at the same time in different places and at different times in the same place. If we are not thinking of universals as abstract entities in Platonic heaven or in the mind, but as individuals out there in the world, it is easier to grasp the idea that they can be perceived. The Nyāya equation of universals and properties might tempt one to think that Nyāya conceives of universals as natural properties in David Lewis’ sense of the term (Lewis, 1983), but such is not the case. Nyāya universals are as robust as Armstrong’s universals: they capture facts of resemblance and the causal powers of things. Naiyāyikas will happily endorse Armstrong’s ‘One over Many’ argument as the main reason for including universals in their ontology (Armstrong, 1978). Udayana puts the point thus: “Causality is regulated by universals, so is effect-hood. It is a natural universal if there is no obstruction [in establishing it]; it is a conditional [nominal] universal when we have to establish it through effort [construction?]” (Kiraṇāvālī, in Praśastapāda 1971, 23).