Certainty is Unquestionable Only when it is Nonconceptual
In the Diamond Approach, this realization is related to the crystal vehicle of the citadel. It is the timeless wisdom leading to nonconceptual certainty. One attains here a certainty beyond doubt, because it is independent of belief, of knowledge, and of any intellectual or experiential category. One is oneself, and sees Reality as it is, with a nonconceptual conviction. The person’s realization has gone beyond knowing and, hence, beyond any doubt or questioning. It is not that he feels certain because he is convinced, for he is beyond convincing. He is not convinced of anything, not even of the truth of his own personal and ascertained experiences and perceptions. He is certain because there is nothing to be certain about, and nothing to doubt. In fact, there is no such thing as doubt, for the mind that doubts is the discriminating mind. This realization becomes what we call certainty only when he contemplates it conceptually. He understands that certainty is unquestionable only when it is nonconceptual, when it is not certainty about anything, but simply the solidity and rootedness of one’s realization of nonconceptual truth. With such nonconceptual certainty he does not need to gauge or rate his realization according to any teaching or wisdom tradition. His realization is totally autonomous, and he accepts it with its uniqueness, just as he accepts the uniqueness of other teachings and realizations. He is free, and this freedom is unutterable delight and uncontainable joy.
The Inner Journey Home, pg. 343
Existential Certainty Needs Direct Experience
So there is always an inference from some perception. And the inference is of something that we are very vague about. When somebody says, “I think, therefore I exist,” what does this person mean by “I”? Is he clear about what he means? And because there is inference, there is no total certainty. There might be logical certainty. There might be commonsense certainty. But there is no real, deeply felt, existential certainty. The certainty doesn't exist in inference because experiential existential certainty needs direct experience, in fact, the most direct perception and experience. The most direct perception and experience is the one of identity, when we are what we experience, when the perception is so direct that what perceives and what is perceived are the same thing. This is exactly the experience of essence.
Experiencing the Sense of Existence with an Unquestionable Sense of Certainty
I feel personal but immense, a person of Being so dense that my substantiality eclipses the physical substantiality of the body. The most definite feeling is a sense of personal existence. I feel intensely real, existing so fundamentally that the mind cannot conceive of this reality. I experience myself as a person, and this person is composed of pure existence. Existence of Being, essential and fundamental, and independent of the mind, forms the very atoms of what I am. I am existence, beyond all thought of existence. The sense of truth and reality is immensely profound; it feels deeper than the universe itself. And this unimaginably real sense of existence has a very subtle sense of being a person—a person not defined by history or mind, not confined by character traits or relationships, but a person who exists, and that is all. The sense of existence has an unquestionable sense of certainty, independent of any content of mind or experience. I recognize at this point that there is no basis for the concern that there will be no personal life if I am not enmeshed in it.
Luminous Night's Journey, pg. 23
Learning with Certainty that We are Always the Absolute
The realization that we are the absolute is different from before. We experience ourselves as the unfathomable empty solidity of the absolute. The absolute is subject in the most direct and immediate way. We experience ourselves not as “I am,” but more like “I” or “II.” But it is not a feeling of identity; it is merely being the mystery, complete abiding as the absolute, and recognizing oneself as such. We learn with certainty that we are always, have always been, and will always be the absolute. We cannot but be the absolute, for only the absolute is. When we are awake to our nature we recognize it as the stupendous silence at the heart of everything, the single source of all manifestation. When we are not awake to our nature we are simply forgetting our nature, and identifying with one of our manifest emanations. Yet, this is only a momentary distraction. We, the absolute, are the one that identifies or disidentifies from any manifestation.
The Inner Journey Home, pg. 422
Recognition that the Personal Essence is Oneself is an Unassailable Knowingness
So the recognition that Personal Essence is oneself as a person is a definite, clear, profound and unassailable knowingness. There is confidence and certainty. One experiences oneself as a human being, as an ongoing-personal beingness. One is real for one exists absolutely, irrespective of the past and of the environment. One is an ongoing sense-of-beingness that is made out of alive consciousness, consciousness that is a palpable presence and not merely the capacity to be conscious. To be is not just to know in one’s mind that one is. To be is to be Being, as existence, and as a substantial presence that is experienced as concretely as physical reality. So to be the Personal Essence is to be a substantial presence, a fullness, a compact consciousness that feels personal.
Pearl Beyond Price, pg. 92
The Certainty that Makes Life Become Significant
You might do some work on yourself and have a wonderful experience, a great insight or state. But how do you know that this wonderful experience is what is needed right now? How do you know that the knowledge you think you’re getting will resolve your situation? The flame must continue. The fire of inquiry needs to be fed, needs to grow, to intensify, to deepen. Our inquiry needs to be directed not at trying to reduce it, but to letting it grow. The flame needs to burn away all the rest, to grow until it answers itself by itself becoming the fulfillment. The fire of that inquiry can burn away all the dross, all the resistance, all the ideas, all the accumulation of the past so you can actually see what is really there, the whole picture in the present moment without needing to depend on anything from the past or on anyone else’s experience. When you know in the moment without any influence, then you can completely be alone with your own truth. Without that, it’s obvious that you can’t know with certainty. Only with that certainty can life become significant. If you know, for yourself, who you are, you will know where you are going, and you will be fulfilled.
Diamond Heart Book Three, pg. 8
The Sense of Certainty Associated with Insight
So there is something in insight that allows us to know directly, without questioning, that something is true, more so than in the experience of ordinary perception. That sense of certainty seems to be intimately linked with the sense of satisfaction, a sense of being more intimate with oneself, closer to oneself. What does it mean to get more intimate and closer to yourself? There’s more warmth, more satisfaction. There’s a sense of freedom and truth. The facts have led us there, although the facts were not exactly what we were looking for. What we’re looking for is that sense of intimacy, closeness, freedom, satisfaction.