It is generally held that the idea of the unification of the disparate communities in Canada (especially the French-Catholic and the English-Protestant) is the central theme of Two Solitudes. Yet through the examination of paired personal relationships (such as Athanese and his two wives and two sons; Yardley and his daughter; Janet Methuen and her two daughters; McQueen and Athanese and Janet, for example) MacLennan also points to the existence of solitudes that are impediments to the full development of personality.
Athanese is unfulfilled by marriage, first to Marie-Adle, the saintly believer with a “little nun’s face” and then to Kathleen, the sensual Irish girl; that is, he is of greater complexity than either, though each represents a part of his needs. Frequently, he alludes to the need for “scientific education” and suggests that this can be obtained only outside the Catholic tradition (Marius attends the University of Montreal, but Paul attends McGill University, on the other side of Mount Royal). Again, the opposite traditions and cultures are symbolized. Paul, by leaving Montreal for Nova Scotia, Oxford, and Greece, represents the liberation from parochialism that MacLennan offers as a solution to the problem of the contiguous cocoons. Ironically, having studied in the university that to Athanese represents science (and hence modernity and anticlericalism), Paul becomes proficient in Greek and a fledgling novelist. He is a liberal thinker, a voyageur, and his impending enlistment is a rite of passage that will surely take him to the goal of self-realization and love.
Similarly, Heather (brought up in the tradition of the ornamental daughter) finds meaning in life only after scrutiny of her own pretensions as a painter and her willingness to assert her individuality, even at the cost of her financial security. Both Paul and Heather have crossed the boundaries imposed by their cultures (their “races” as they are called in the novel) and have found self-awareness and love. Through them, the two solitudes that afflict Canada are breached.
Although Two Solitudes is a thesis novel, it is not obtrusively didactic: Puritanism is shown as a destructive force, but so is sectarian dogmatism. Protestant-dominated commerce is no better than Catholic-controlled agriculture, for each is another version of the basic malady.