Regarding the question you raise concerning my post on “Changing Religions, Changing Churches“, it seems there are two distinct issues at stake: (1) Is there a genuine doctrine of theosis in the Western Church? (2) If so, can one find among Western mystics a method that is fully adequate to the doctrine?

Surely no one will dispute the fact that the Christian East stresses theosis in a way one does not find in the West, where, with certain important exceptions, even the greatest mystics seem content with what one might call the “divine proximity”—a visio beatifica in which God remains forever other. Whereas in the East, even among those who aren’t especially known for their mysticism, the emphasis is always on the supreme goal of “participation in the divine nature” (2 Pet. 1:4): “God became man that man might become God.”

As I say, there are Western exceptions, most notably Eckhart, who obviously goes far beyond a visio or mere beholding. But the question in his case is whether we’re really given a method, a step-by-step set of instructions as to how we may become so completely “poor” as to be “quit of God” and to realize that “I am my own First Cause” (I quote here from his sermon on the beatitude “Blessed are the poor in spirit, for theirs is the kingdom of heaven” [Matt. 5:3]; see Chapter 70 of my Not of This World).

Mind you, I yield to no one in my admiration for this greatest of doctrinal masters, whom I regard as no less than a summit among Christian sages. But it seems to me there’s very little, if anything, in his teaching—or that of his fellow Rhenish mystics—to tell us how he himself came to be the Truth he knew. Indeed I wonder sometimes whether his sometimes deliberately scandalous, in-your-face provocations may not be for the unprepared reader an occasion for delusion and heretical fantasy. After all, the self-described “post-denominational priest” Matthew Fox is hardly alone among New Agers in espousing what he supposes to be an Eckhartian vision.

As for the other Western writers you mention—John of the Cross, on the one hand, and the 13th and 14th century English mystics on the other—I would question whether their teaching is really on the same level as Eckhart’s, whether for them union is truly a matter of identity, and not rather of unity or perhaps unicity; I’m referring here, as you’ll see, to the three concluding sub-sections of Not of This World. But even if these saints do fully envision the goal of theosis in its ultimate sense, there remains once again the same absence of an explicit method.

One hears a great deal in these authorities, of course, about the various stages and “mansions” one may expect to pass through as one traverses the spiritual path. But as to the passing or traversing itself, the actual procedures for traveling, the reader is left to deduce or construe the tacit requirements. Detailed instructions regarding such points as breathing and posture and the direction and control of attention—instructions of a kind that may be said to constitute a genuinely Christian “yoga”—seem almost entirely lacking.

By contrast, the ascetico-mystical tradition of Eastern Christian Hesychasm is incredibly detailed. The difficulty here, admittedly, is that one is often obliged to wade through a considerable undercurrent of bhaktic sentimentality, and the exegesis of scripture in the Hesychast authors is by no means always of an anagogical order. Nonetheless, they never leave us in any doubt as to the practicability, one might even say the “scientific” repeatedly, of the method they follow. “Do this,” they say—make these metanoias, repeat these invocatory formulas, move your breath and attention to these parts of your body, distinguish and disrupt the logismoi (thoughts) in this particular order—”and, by God’s grace, you too will become ‘infinite and without origin'” (St Gregory Palamas).