Indeed, the two proofs of God's existence that Descartes presents in the third and fifth Meditations rely entirely on the three debatable axiological positions we have identified. As we shall see, he deduces God's existence from His value.

The first proof may be summarised as follows: in the 'I', whose existence I have just demonstrated, I find the idea of God. This idea is therefore indubitably present in my mind. How do I move from the existence of the idea to the existence of its object—that is, from the formal reality of the idea to its material reality? In other words, how do I prove that God truly exists, rather than being merely an idea in my mind?

This is where Descartes brings in the first axiologically dubious position we identified. The idea of God is that of a perfect being (as previously defined), which implies an infinite God—since to be infinite is to exist without limitation, equating being with perfection.

Descartes then deduces the real existence of God from the infinite nature of this idea, by means of the second dubious axiological position: that the cause is always more valuable than the effect.
Whence can this idea of an infinite—that is, perfect—God arise in me? What could be its cause? Only a being that is itself infinite, and therefore perfect, since something of lesser value cannot be the cause of something of greater value. God therefore exists as the necessary cause of the idea I undoubtedly find in myself: The more carefully I concentrate on these attributes, the less possible it seems that any of them could have originated from me alone […] It is true that my being a substance explains my having the idea of substance; but it does not explain my having the idea of an infinite substance. That must come from some substance that is itself infinite ¹.

We can see, then, that Descartes' dubious axiology is deeply embedded in his logical reasoning: his logic is built upon his axiology, and his judgements here are fundamentally value judgements.

The second proof of God's existence, presented in the fifth Meditation, may be summarised as follows: the idea of God is that of a perfect being, and what exists is more perfect than what does not (or, put differently, perfection, value, and existence are synonymous). Therefore, God exists.
This celebrated argument has been misleadingly termed the 'ontological argument'. In reality, it is an ontological-axiological argument—a logical monster, attempting to derive an ontological reality from an axiological position.

Kant's criticism of the ontological argument likely missed its target. In using the example of the hundred thalers to show that existence is not a predicate like any other, Kant moved onto ontological ground, which could be—and was, by Hegel—countered with other ontological arguments. The argument should perhaps be approached from the perspective in which it truly operates: that is, examined as an axiologist rather than as a logician.
It rests on the first two questionable axiological positions we identified: that perfection has value, and that perfection and being are identical.

We could counter this by proposing that what holds value is nothingness, and that God, as the supreme value, therefore does not exist. Alternatively, we could argue that perfection is not the supreme value, and that we cannot therefore deduce God's existence from His perfection. In short, Descartes can be met with a range of opposing axiological judgements. One might also deny that any ontological conclusion can be derived from an axiological premise, the two spheres being distinct. Finally, one could argue that it is impossible to derive a certain ontological judgement from a questionable axiological position.

As we can see, Descartes' axiology underlies his conclusions throughout. In the Cartesian approach, then, we find not a purely logical proof of God's existence, free of value judgements, but rather a reliance on a questionable axiology to move beyond the certainty of the cogito—which is purely logical.
What accounts for the shift, from the second to the third Meditation, from a purely logical perspective to an axiological one? It lies in the fact that Descartes does not attribute value to the 'I'—at least not at this stage—while, as we have seen, he covertly incorporates value into the very definition of God. So long as Descartes remains with the cogito, or the demonstration of the 'I's' existence, no consideration of value is invoked. The moment he turns to God, however, the notion of value enters the argument, even if under the guise of 'perfection'.

The epoché contained within Descartes' radical doubt is confined to questions of fact—specifically, of existence: 'Does X exist? I must doubt it,' says Descartes, leading him, over the course of the first Meditation, to doubt the existence of everything presented to him by his senses, his reason (mathematical 'realities' included), and even God.
For Descartes, the question is 'Does God exist?'—never 'Does God have value?', which he never doubts.
This becomes apparent as early as the first Meditation, where he calls the truth of mathematics into question by imagining that God might be powerful enough to deceive us. He immediately reassures himself, however: God is so good that He could not do that; an evil genius might, but not God. The concept of the evil genius thus stands as a symptom of Descartes' inability to conceive of a God without value—prompting him to invent a separate figure that combines divinity with imperfection.

The whole of Descartes' enterprise is oriented towards proving that God exists: And just as I can imagine a winged horse even though no horse has wings, so I can attach existence to God in my thought even if no God exists ²—and the objections raised against him (by Hobbes, for instance) proceed from the same angle: does this idea of God truly exist within us or not? To this Descartes replied: Also, someone who denies having any idea of God, in my sense of 'idea', is making the most impious confession he could make ³.

It is the existence of things that poses a problem, not their value. This gives rise to the following hypothesis: the problem of values may never have occurred to Descartes at all. Be that as it may, despite its ambition, Descartes' celebrated 'hyperbolic' doubt is not truly radical: it leaves the entire sphere of values untouched. What undermines the Cartesian approach is that, following the Cogito, Descartes relies fundamentally on dogmatic and questionable value judgements in his claim to have reached the indubitable. In reality, he appears to remain trapped within the confines of the ego—unable to move beyond it to demonstrate the certainty of God, and subsequently of the world, as he had intended.

In seeking to understand the nature of the axiological epoché we are proposing, we turned to Descartes' model as he attempted to explore the possibility of radical doubt. We found that Descartes pursued a different kind of epoché—an ontological one, concerned with judgements of reality or existence—which therefore could not serve as a model for our own inquiry. We also concluded that this approach failed, because, being covertly grounded in an axiology, it stood in need of an axiological epoché—something conspicuously absent from Descartes' work.

One interesting insight may nonetheless have emerged: our search for the value of things is distinct from any enquiry into their existence. We do not ask whether something exists, but whether it has value.

1. Metaphysical Meditations, III
2. ibid, V
3. Lettre à M. Clerselier, Réponses aux 5èmes objections de Gassendi