By the way, Descartes was not a skeptic, despite the game he plays with his "method of systematic doubt" in, for instance, the first Meditation.
Very important point...Because many sceptic debunking circles act like believers without even knowing that they are believers...
The doubt method is never itself subject to doubt by them , and instead of a suspension of belief, their doubt is only an expression of a belief in the non value of any belief...
Which is the opposite way Descartes use his doubt method and the opposite way Husserl in his Cartesian meditation use Descartes to reveal the deep intentionality of meaning itself...The Method of Husserl is called : epochè...
Each phenomenon is then perceived for a consciousness as a meaning not as a fact...
The usual sceptic reject the meaning with the associated fact which are believed rightfully or not to be wrong... They throw the baby with the muddy waters... An error Descartes and Husserl dont commit...
What cannot be rejected and what must be true is the meaning of meaning itself...An experience of the conscious intentionality itself...
What is interesting is the way Arthur Young depict the meaning of meaning in a pragmatic way to be an angle... The great thinker and scientist Charles Sanders Peirce, rejecting nominalism, will create a complete new field of science and philosophy called " semiotic" , where the meaning of meaning will be described as a sign... But Arthur Young is way simpler to understand than ALL writers i spoke about...
For Young all meaning is an angle, for Descartes all meaning is an "i am" moment, for Husserl all meaning is a consciouness act, for Anirban Bandyopadhyay all meaning is music, even time is music and for Alain Connes too numbers are music and not the reverse...
Now what is the relation between, meaning, sign , angle, numbers, music, time, and consciousness: in Anirban model all that is a system of nested clocks which express the way we synchronized ourself with all that exist... It is "a conscious machine", the living body in a conscious universe...
I will not go beyond here to speak about the soul... And about the way our soul is not reducible to the living body, no more than the cosmos is reducible to the physical unique universe we live in for the time being...