Meditating with Descartes — Consciousness, God, and the Nature of Mind

In his Third Meditation, René Descartes delves into the nature of the mind and its relationship to existence in a way that I find extraordinary — and the further I go in Vajrayana practice, the more extraordinary it becomes. Having established in the Second Meditation that he exists as a thinking thing, Descartes now turns to examine the contents of his mind more carefully. What he finds there stops him cold. He finds the idea of God — infinite, perfect, omnipotent, the source of all things. And he cannot explain where it came from. This is the heart of Descartes consciousness inquiry, and it is where the comparison with the Buddha Dharma becomes most alive.

The Third Meditation — What Descartes Was Really Asking

Descartes’ exploration revolves around the idea that because he, as a thinking being, can be certain of his thoughts, it confirms his existence as a thinking thing. This line of reasoning leads him to assert the inseparable connection between the mind and the self — the centrality of consciousness in defining one’s existence. But having established that, he finds himself facing a new and deeper question. The cogito told him that he exists. The Third Meditation asks: what kind of mind is this, and where do its contents come from?

Descartes is working within what philosophers call the principle of causal adequacy — the idea that a cause must contain at least as much reality as its effect. You cannot get more from less. A finite, imperfect being like Descartes cannot produce, from nothing, the idea of an infinite and perfect being. The idea is simply too large. Too complete. If it exists in his mind — and it clearly does — something at least as large and complete must have put it there. This is Descartes’ proof of God’s existence, argued entirely from the contents of his own consciousness.

What I want to sit with here is not the theological conclusion but the inquiry that drives it. Descartes is asking one of the most fundamental questions a mind can ask about itself: where do I come from? What is the source of what I know? Is there something larger than me that I am, in some way, an expression of?

The Idea of Infinite Perfection — Descartes Consciousness and Its Source

The key move in the Third Meditation is Descartes sorting his ideas into three categories: those that seem to come from outside him through the senses, those he appears to have invented himself, and those that seem to be innate — present in the mind regardless of experience. The idea of God falls into the third category. It does not come from the senses. He did not invent it. It is simply there, a complete and fully-formed idea of infinite perfection, present in the mind of a finite and imperfect being.

This creates the causal problem. If Descartes is the finite source of all his ideas, how does he contain the idea of something infinitely greater than himself? His answer is that he cannot be the source. Something infinite and perfect must have placed this idea in him — and that something is God. The existence of the idea in his mind is itself the proof of God’s existence outside it.

— Descartes, Third Meditation

🏛️ “By the name God I understand a substance that is infinite, eternal, immutable, independent, all-knowing, all-powerful, and by which I myself, and every other thing that exists, if any such there be, were created. Now these advantages are so great and so eminent, that the more attentively I consider them, the less I feel persuaded that the idea I have of them owes its origin to myself alone.”

The question he is really circling — and this is the question that connects directly to Vajrayana Buddhism — is whether consciousness is the source or the vessel. Is mind the container for an idea of the infinite that was placed there from outside? Or is mind itself, in its nature, the infinite it is looking for?

What Thinks? The Mind as Non-Composite

Building on the cogito, Descartes extends his inquiry into what the mind actually is. He asks, with a directness I have always admired, what exactly this thinking thing that he has confirmed himself to be is made of. What is a thinking thing? What are its parts?

🏛️ Descartes — Third Meditation

“But what then am I? A thing which thinks. What is that? A thing which doubts, understands, affirms, denies, wills, refuses, and which also imagines and feels.”

None of which has a corporeal source. This is Descartes’ own conclusion — and it is a remarkable one. Doubting, understanding, affirming, denying, willing — these do not come from the body. They are not located in any particular piece of matter. The mind as Descartes defines it here is functionally non-material. It does not have the properties of physical things. It cannot be divided, measured, or located in space.

Descartes suggests that the mind is distinct from the body and that its essence lies in the act of thinking itself. This separation allows him to affirm the existence of the mind as a thinking substance, independent of material or physical attributes. By emphasising the mind’s capacity for thought as its defining characteristic, he highlights the intrinsic connection between the mind and self-awareness — the mind not as something that has consciousness but as something that is consciousness.

Vajrayana Buddhism — Mind as the Source of Everything

Mind is not put together. It is the ground from which everything arises. — QP

In Vajrayana Buddhism, the nature of mind is understood in a way that both resonates with and goes beyond what Descartes arrived at. Where Descartes posits that mind is not composite — not assembled from material parts, not dependent on the body for its existence — the Vajrayana tradition has been articulating this with extraordinary precision for centuries. Mind is not put together of any parts or subparts and is therefore not dependent on anything else as its source. In fact, in the dharma view, mind is seen as the source of all other things.

This is not a casual or poetic claim. It is a rigorous philosophical position with an enormous body of contemplative literature and direct experiential investigation behind it. The Mahamudra and Dzogchen traditions in particular have mapped the nature of mind in extraordinary depth — its luminous quality, its non-composite nature, its primordial presence prior to all conceptual construction. What Descartes arrived at through logical reasoning, Tibetan practitioners have been exploring through direct meditative investigation for generations.

“Mind itself has no birth, no cessation, no colour, no shape. It is not found outside, not found inside, not found anywhere in between. It is not made of anything. It is the ground from which all appearances arise and into which all appearances dissolve. This is what is meant by the nature of mind.”

— Kalu Rinpoche, Luminous Mind

What Kalu Rinpoche is pointing at — and what the entire Mahamudra tradition is pointing at — is that mind is not just non-composite in the sense Descartes meant, not merely free from material parts. It is primordially pure, naturally luminous, and self-aware. It is not a vessel for the idea of the infinite. It is, in its nature, what that idea is pointing toward. The infinite perfection Descartes finds as an inexplicable idea in his mind is, from the Buddhist perspective, the nature of the mind doing the finding.

This is where the Vajrayana understanding both confirms and completes Descartes’ inquiry. He was right that the idea of infinite perfection cannot have come from a finite being looking outward. He was right that its source must be something greater. What he did not consider was the possibility that the source is not outside the mind but is the mind — the nature of mind, prior to all the doubting, affirming, and constructing.

Are We God? The Question Descartes Couldn’t Answer

The original title of this page — Are We God? — is a question that Descartes raises implicitly and never fully answers, because the framework he is working in does not give him the tools to answer it. Within his Christian context, the answer is clearly no. We are finite creatures. God is infinite and separate. The idea of God in our minds is proof of God’s existence outside us, not proof that we are God.

The question Descartes was never free to answer — QP

But the question is more interesting than the answer his framework permits. If the idea of infinite perfection is innate in every human mind — not derived from experience, not invented, simply present — what does that tell us about the nature of the mind that contains it? Descartes stops at the theological conclusion. The Buddha Dharma keeps going.

Buddha-nature — tathāgatagarbha — is the teaching that the seed of complete awakening is present in every sentient being without exception. Not as a foreign element placed there by an external power, but as the intrinsic nature of mind itself. This is not the claim that we are God in any theistic sense. It is the claim that what we are, at the most fundamental level, is not different from what all the traditions are pointing at when they use the word God — the infinite, the luminous, the source.

Descartes’ meditation and Buddhist teachings both underscore the transformative infinite capacity of the mind to illuminate the nature of existence and lead the individual towards a deeper understanding of self and reality. Where they diverge is in how far that illumination is allowed to go. Descartes uses the infinite idea as a signpost pointing outward toward an external God. The dharma uses the same recognition as a signpost pointing inward — or rather, prior to the distinction between inward and outward altogether.

The Fourth Meditation is where Descartes turns to the question of truth, certainty, and God as the guarantor of knowledge. We will meet him there.