To read Byron's poetry as philosophy without reference to form is to miss the poetry's philosophical significance. This seems most pressingly true in the case of Don Juan, a poem in which language is untethered within the precincts of intellectual history with effects that are at once critical and creative. In what follows I want to think about this complicated meeting of philosophy and poetry, something, I suggest, in which Byron was deeply interested, with primary reference to what seems in many ways the poet's most obviously ‘philosophical’ literary work, Cain.

Byron began writing Cain in Ravenna on 16 July 1821. Six months later he would resume Don Juan after having written nothing of his sprawling epic for over a year. The new cantos of Don Juan, beginning with canto vi, would display several significant changes from previous instalments, notably an increase in digressive material and a closer integration of this into the narrative of the story. These newly extensive digressions, which punctuate (and frequently open) the later cantos of the poem, have a strong philosophical flavour, a fact it seems reasonable to connect with the composition of Cain and its strong speculative themes. Despite their chronological and thematic proximity, however, Cain and Don Juan appear to have little in common in terms of scope, tone and form. Don Juan is on the whole a much fuller, more diverse and more comically evasive poem, one wonderfully uncontained by its philosophical interests and brimming with energies that seem the antithesis of argumentative rigour. Cain, by comparison, looks far more obviously and directly like something we can call a ‘philosophical poem’; it is easier to read, that is, as a vehicle for its grounding polemical commitments than as a poetic shaping to the unargued contours of life. These differences have tended to mean that critics have approached the two works not only in isolation from one another, but with very different assumptions and aims: where serious critics of Don Juan have been minded of the poem's fragmen–tariness and resistance to systematic thought, Cain 's commentators have often looked at the play as something closer to a manifesto, as containing a definite philosophical or religious message.