From nethermost nescience to the apex of omniscience, all states of knowledge are without any ultimately real foundation whatsoever—and the same applies to the very states themselves.
Without the recognition of this basic fact, it is impossible to ascend from ignorance to knowledge. For if things did have an intrinsically existent foundation or essence, it would not be possible for knowledge to grow and develop since it would be completely fixated on that particular state of knowledge, and we would fall prey to the illusion that we can actually account for the way things are in a definite and timeless way.
Thus genuine science and genuine religion do not seek out or base themselves on absolute truths, but are open-ended processes geared towards the ascertainment of practical truths. Beyond the myopic horizons of dogmatic science or dogmatic religion lies the boundless expanse of sensitively responsive wisdom.
A skeptic may retort that I have just contradicted myself by asserting ultimate foundationlessness as an ultimate foundation, but they should understand this:
my statements are to be understood as meta-metaphysical, not metaphysical;
which is to say that ultimate foundationlessness refers to the impossibility of a true metaphysical account of things and should not itself be mistaken for a metaphysical account of things. Thus this truth of foundationlessness is not an absolute truth but a practical truth that functions to bring the knower to their own sensitively responsive wisdom.