Many philosophers, especially those who are tagged as “philosophers of life” have a considerable contribution in approaching this great issue. Henri Bergson is maybe the most significant on the subject.
But what theatre -and I mean ancient Greek tragedy above all- has as a unique attribute is that more than any philosophic/epistemological approach presents the totality of life in the most direct, simple and open to endless “readings” way.
Is its certain type of dialogue the core of tragic element? Maybe, at least for some. But tragedy at the same time also contains the monologue. Does this mean that dialogue is incomplete without some monologues? Perhaps. In some way dialogue is loaded either with releasing or restraining dramatic tense. A person, a human being, is maybe unable to represent his totality through the dialogue. So he/she needs a monologue which, of course is always a covered dialogue since it presupposes the symbolic “Other”. At the same time the rational, controlled, “apollonian” element is confronted with the “Dionysian” and neither has the final control but they co-exist. Gods, mortals, kings, people, chorus and personae, lyric and epic forms, wise advisors and fools interact presenting this totality of life which is broader than any mental or sentimental attempt to catch.
Tragedy was the birthplace of democracy as we historically know the term, the Athenian democracy. Every enlightened citizen was aware that what was going on in the Agora was only a part, a fragment of an older (tragic) culture which was fading out. Orality in the Agora was the best they could do to remember and preserve this tradition. Plato felt bound on this tradition that’s why he wrote in dialogic (but indeed a pseudo-dialogic) form. This fading out procedure resulted to rhetoric speeches and the rhetoric form of democracy (which resembles with the modern politics).
So searching for the totality of life means to come back to your so well phrased axiom.
Take a look at www.demothen.blogspot.com