Essentialism, Interactionism and Nominalism, the three sibling metaphysical positions filled in the same pass, each name one historical figure as principal proponent directly in their own text (Aristotle, Descartes, Ockham). Presentism's own text sets out the position and its objections in the same style but names nobody as having first defended or best defended it.
What would resolve this A citable history-of-philosophy source identifying the position's clearest or earliest defender, whether an ancient or medieval figure arguing from ordinary intuition about the reality of the present, or a modern one such as the logicians who built formal tense logic specifically to defend it.
OpenHistory of philosophyEdward N. Zalta and Uri Nodelman (eds.), Stanford Encyclopedia of Philosophy