As an elevated, timeless form of literary creation, poetry has always raised fundamental questions regarding its nature and functions. Should poetry be defined through its distinction from prose and the use of poetic language? Is it a self-contained artistic entity or a product of an interactive nexus between the poet’s imagination and the external world? Such elemental concerns have been addressed not only in critical writings but also in poems. An ars poetica poem is a “metapoem,” a self-reflective poem about poetry, aiming to probe into the nature of poetry and poetic language. Adopting an analytic-descriptive method, this qualitative, library-based study intends to examine three major ars poeticas from three different literary eras, namely Horace’s classical Ars Poetica (c. 20 BCE), which later shaped the foundation of the Neoclassical theory of literature, Archibald MacLeish’s “Ars Poetica” (1925), which can be deemed a Modernist-Imagist poetic manifesto, and Czesław Miłosz’s “Ars Poetica?” (1961), which succinctly sums up Postmodernist literary theory in a poetic fashion. Through a close reading of these three “(meta)poems,” it is suggested that ars poetica has a symbiotic connection with the intellectual ambiance of its time and that the nature of poetry itself has always been one of the perennial thematic concepts of poetry without necessarily turning into didactic verse treatises. The findings of this study can, thus, carry intriguing implications for teaching poetry as they reveal the potentials of poetry for philosophizing about the aesthetic and cognitive values of poetry in a more capturing and thought-provoking manner.