“When we realize our faults, we must never ask, ‘What should I do?’ because knowledge is itself the cure.” I agree that this citation from Schuon is pertinent to your predicament. What he has in mind, by the way, is a passage from the Bhagavad Gîtâ: “There is no lustral water like unto knowledge.” In any case, having quoted him, you proceeded to ask me, “What is the criterion for the kind of knowledge that comprises the cure?”
It goes without saying that the knowledge in question must be “ontological”, that is, rooted in our being, and not merely of a theoretical, let alone conjectural, order. I often think of the following lines from Coleridge in this connection:
If to mint and to remember names delight thee, still arrange and classify and pull to pieces, and peep into Death to look for Life, as monkeys put their hands behind a looking-glass! Yet consider, in the first sabbath which thou imposest on the busy discursion of thought, that all this is at best little more than a technical memory: that like can be known only by like: that as Truth is the correlative of Being, so is the act of Being the great organ of Truth: that in natural no less than in moral sciences, quantum sumus, scimus” (Aids to Reflection).
The Latin maxim means, “As much as we are [or “to the extent we are”] we know”, which implies the doctrine of degrees of being; with apologies to Shakespeare, “To be or not to be” is not the question, for one may “be” more or less fully—because more or less consciously—depending upon which of the several levels of the microcosmic hierarchy one identifies with, whether body, soul (including mind, will, and emotions), or Spirit (see 1 Thess. 5:23). And this level of identification is dependent in turn on the extent to which we have begun to die to attachment, in keeping with Plato’s dictum: “Those who pursue philosophy aright study nothing but dying and being dead” (Phaedo).
Schuon, as you may remember, reduces this Coleridgean insight to a kind of alchemical tincture in saying, “To know That which is one must be That which knows.” The upper case “T” in this formulation points above all to the opening pronoun of the Upanishadic Tat tvam asi, that is, to Nirguna Brahman, the unqualified Principle. But the basic truth at stake here applies no less at lower levels of Reality, at each of which authentic knowledge requires an adequation, and not merely a confrontation, between knower and known.
As for the “criterion” you ask about, such knowledge is surely its own criterion, for the truth it discerns—by way of “the mind’s self-experience in the act of thinking” (to quote Coleridge again)—must be self-evident. Were there some extrinsic standard of measurement, something else in view of which or compared to which a truly “curative” knowledge could be known to be such, this standard, and not the thing measured, would be the cure. The moral of all this, of course, is koanic: as long we’re looking to be healed we won’t be, or not at least fundamentally so—not at that deepest level where “the lustral water” is ever flowing. For finally the cure is not a means to becoming cured; it’s the discovery that we’re cured already, having never been ill.