In SN 35.93 quoted below, it reads intellect-consciousness arises in dependence on the intellect and ideas, but if this consciousness is also a thinking about the work of intellect on ideas then it in itself is an intellect. and if so we have to look for another consciousness which higher and the search continues ad-infinitum.
This, of course, is not my own though it's a classic platonic thinkers response to Descartes's misguided saying Cogito ergo sum ( I think, therefore I am), quoted below is from Plotinos Ennead Book Nine explaining the relation of intellect and consciousness.
"In dependence on the intellect & ideas, there arises intellect-consciousness. The intellect is inconstant, changeable, of a nature to become otherwise. Ideas are inconstant, changeable, of a nature to become otherwise. Thus this pair is both wavering & fluctuating — inconstant, changeable, of a nature to become otherwise.
PLOTINOS: - SECOND ENNEAD, BOOK NINE.
Though there be a difference between thinking, and thinking that one thinks, these two nevertheless constitute a single intuitive consciousness of its actualizations. It would be ridiculous to deny such a consciousness to veritable Intelligence. It is, therefore, the same Intelligence that thinks, and that thinks that it thinks. Otherwise, there would be two principles, of which the one would have thought, and the other consciousness of thought. The second would doubtless differ from the first, but would not be the real thinking principle. A mere logical distinction between thought and consciousness of thought would not establish the (actual) differences between two . Further, we shall have to consider whether it be possible to conceive of an Intelligence which would exclusively think, without any accompanying consciousness of its thought. If we ourselves who are entirely devoted to practical activity and discursive reason were in such a condition, we would, even if otherwise considered sensible, be insane. But as true Intelligence thinks itself in its thoughts, and as the intelligible, far from being outside of Intelligence, is Intelligence itself, Intelligence, by thinking, possesses itself, and necessarily sees itself. When Intelligence sees itself, it does not see itself as unintelligent, but as intelligent. Therefore in the first actualization of thought, Intelligence has the thought and consciousness of thought, two things that form but a single one; not even logically is this a duality. If Intelligence always thinks what it is, is there any reason to separate, even by a simple logical distinction, thought from the consciousness of thought? The absurdity of the doctrine we are controverting will be still more evident if we suppose that a third intelligence is conscious that the second intelligence is conscious of the thought of the first; we might thus go on to infinity
