In Descartes, we no longer have a transcendence of the Idea or Form (as in Plato) or the transcendence of Being (as in Christianity) but the transcendence of a thinking subject. Now it is the I, as an expression of consciousness, which is privileged in relation to experience. This leads Descartes to assert a dualist ontology, claiming a fundamental distinction between mind and body. It takes little guesswork to figure out which of the two attributes – mind and body – will be placed on the side of transcendence and which will be placed on the side of immanence. It takes little guesswork too to figure out which of the two substances is considered superior, is giving priority over the other. Mind is superior, is transcendent, precisely because it is “immaterial”, precisely because it is not-body. If this form of transcendence continues to be dominant in contemporary society (even as we become more secular, and more suspicious of the notion of universal truths and moral absolutes), it is because it conforms to our common-sense perception of the world; each of us perceives the world as though we are at its center, with the freedom to remove ourselves from the world when we feel the necessity to reflect, to cogitate, and so on. We feel as though we are transcendent to the world, no more so than when we are thinking.
Needless to say, this mode of transcendence is no more acceptable to Deleuze than the other two we considered. There is, for Deleuze, no "mind" or "consciousness" or "self" or "I", or whatever you want to call it, which exists outside of life (or outside of time). There is only mind or consciousness or self or I, or whatever you want to call it, that exists within life, that exists on an immanent plane along with all the other entities that make up the world, all the other entities that make up our world – the only one we have.