Canada has two celebrated savants: the flashy fellow who calls himself Marshall McLuhan, and the sober and redoubtable Northrop Frye, probably the best literary critic of his generation. The magic word in Frye is ""archetypes,"" around which run the structural principles of Western literature as they present themselves through the context of classical and biblical values, myths, and symbols. But Frye's approach is ultimately scientific in the Aristotelian sense, and his method presupposes a belief in a ""total literary history,"" basically both atemporal and asocial, though not without an ""implicit moral standard."" He might, therefore, seem an unlikely candidate to make so chaotic and slippery a subject as ""the modern century"" come alive for us. Happily, his Whidden Lectures on this theme, delivered recently at McMaster University in honor of the Canadian Centennial, show Frye in splendid form--indeed, his aerial view of culture from Baudelaire to Genet, from a hierarchical aesthetic to an absurdist or apocalyptic one, makes a genuinely sound and attractive summing up. His sense of hidden relationships is always provocative, as when he notes the odd interplay between socio-political decentralization and ""attempts to 'purify' a language,"" or as he develops the notion of an evolving open mythology and the prophetic function modern art has unconsciously assumed. A short work written with economy and grace.