In Metaphysics Λ7 1072b30–1073a3, Aristotle introduces a Speusippean theory according to which ‘what is most beautiful and best is not en archēi’. Through a detailed analysis of the passage, I argue that Aristotle’s refutation of Speusippus’ thesis is favoured by the introduction of the seed example, which conflates both ontological and temporal priority. The elements gathered from the analysis of Aristotle’s polemical strategy will support a broader conclusion: Speusippus’ reason not to characterise his principle(s) as (the) good is related to (...) the problematic relationship Forms and sensibles had within Plato’s account, or, in other words, participation. (shrink)