This article offers a new examination of the place of philosophy in Catullus’ Carmina. It focuses on Egnatius, the ‘smiling Spaniard’ of poems 37 and 39, and argues that Catullus’ attacks on this character make use of many standard invective tropes against Epicureans in the late Republic. More than merely an opportunity to show off his whitened teeth, Egnatius’ smile may well have been proof of his philosophical detachment and ataraxia. Yet Catullus maliciously misrepresents this mark of Epicurean virtue as a social gaffe, and an unflattering reminder of Egnatius’ provincial origins. I then reinterpret poems 37, 38, and 39 as a poetic series unified by the ‘banalization’ of philosophical ideas. Ultimately, Catullus creates his own singular voice – the arbiter of style and taste – by representing aspects of other people's behaviour as trite and ordinary. To banalize is an act of power, and it is a weapon that Catullus wields to articulate a sense of difference from other poets and thinkers in his intellectual world.