I believe that even the best scientists and philosophers are far from being able to understand the world around us. For example, I believe that reality cannot be known while living in this world. This renders the knowledge of science and philosophy to be a figment of one’s imagination.
Your claim is a bit bizarre, because it sounds somewhat circular. If we are unable to know reality, we are unable to know the truth. But presumably you intend your claim to have meaning—that is, you intend it to reflect something real? If there is no possibility of knowing what is true or real, how can your claim have any coherence? To say, in other words, “reality is unknowlable,” would seem to imply that you wanted that statement to represent something real. It’s a paradox giving us ultimately non-meaning.
But rather, on the contrary, as St Thomas tells us, “we can know the truth in reality.” If we could not, we would not be able to know anything with any kind of certainty, including the existence of God through natural reason. And while you may think that faith, without any assurance of reality might suffice, faith itself would be totally detached from what is real and therefore irrational.
God is the supreme reality of realities, and in knowing God, we can and do know what is real. Philosophy is not an abstraction; it is a gift from God that we might know Him through what is real. Pope St Benedict put it very well in a March 2011 speech:
“Neither material things, nor money, nor buildings, nor any of the things I can possess constitute the essential, or reality. The reality of realities is God. This invisible reality, seemingly far from us, is the reality. Learning this and thus changing the direction of our thinking, to truly assess how the real, which must orient all things is God, it is the words, the word of God. This is the criterion, God, the criterion of all that I do. This really is conversion if my concept of reality is changed, if my thought is changed. And this must subsequently penetrate each individual aspect of my life: in my judgement of every single thing to take as my criterion what God says about it.”