The problem in attempting to define any
substrate has been analysed by the post-modernists as leading to aporia
(insoluble paradoxes). Simplistically this is because stating what something IS necessarily entails its juxtaposition with what it IS NOT. i.e. thesis and antithesis are essentially co-relational.
Now for the purposes of what we call "science", the properties of what we want to call "essential stuff" can only be evaluated in terms of the contextual goals of science (e.g. prediction and control). If you want to promote "intelligence" to this role over "matter" or "energy" you can only do so in terms of establishing its greater scientific functionality
, not its assumed ontological status.
Interestingly, in the recent book "Quantum Theory: Whatever Can Happen Does Happen" (Cox), a statement is made about electrons which is something like...
"according to the Pauli Exclusion principle, every electron in thde universe knows
what all the others are doing".
....but the author immediately dismisses any "mystical holistic nonsense" regarding thi,s as he is claimming the mathematics is merely functional.