This article, derived from my forthcoming book, examines how the irrational was represented through the juxtaposition of Dionysus and Apollo. Ever since Nietzsche’s Geburt der Tragödie, the polarity of the two gods has been codified in Western culture. However, while their discrepancy as opposites has been widely appropriated, little attention has been given to their similarities which can be found in classical art and literature and again from the Renaissance onwards, when Plato’s praise of “madness” was rediscovered, and images of Dionysian character were re-produced. This article briefly traces back the roots of Nietzsche’s ideas and confronts these with examples from the visual arts. It also re-considers the ancient Dionysus and his transformations across time, investigating which aspects of the god were favoured versus others. Bacchus, “id est vinum” recited a popular formula, but from Michelangelo to Caravaggio and beyond, this was not the only Dionysian guise to be known. While often depicted as a merrymaking god of nature, darker aspects could be chosen. It is the madness and disorder, as well as the reasons for their revelation (or omission) that are explored, in the belief that these provided the sources for Nietzsche’s dualistic formulations and many a modern “coniunctio oppositorum”.