THE FIRST GREAT PHILOSOPHICAL question is: What is? The second, which naturally follows, is: How do we know what is? The first question is about being, the second is about truth.
Truth is relative to being, for “truth” means“the truth about being.” “An orange is round” is true only because an orange is round.
Jesus’ answer to the first question, the question of being, was Himself. It was not to point but to be, to be “I AM.” So His answer to the second question, the question of truth, is also not to point to anything else as the truth but simply to be Himself the truth: “I AM the truth.” ( John 14:6)
Thus the supreme irony of Pilate cynically addressing the philosophers’ great question “What is truth?” to the eternal, perfect, absolute, divine, eternal truth Himself, made incarnate and concrete and personal and standing before him, condemned.
Pilate’s skepticism implicitly complains: “How am I supposed to know that great philosophical will-o-the-wisp, ‘truth’? Can I see it? Can I touch it?” And Jesus answers: “Yes. In fact, you can crucify it.”
Peter Kreeft, Philosophy of Jesus (pages 47-48)