Imagine a family of people who are color-blind. A tragic plague wipes out the rest of the human race. Over centuries, this one family repopulates the globe. The universal experience of all people on earth is to see green and blue as the same color. Their languages, art, music, and cultures all agree on this. Beautiful poems comment on how lovely it is that the grass and the sky are painted with identical hues.
Their experience is universally agreed upon, supported by every aspect of their experience. Their languages don’t even have separate words for “green” and “blue”, because it never occurs to anyone that these are two distinct colors.
In our world, the only reason color blind people know they are color blind, is because the rest of us are able to distinguish between colors, and we communicate this fact to them. But if all people were color blind, color blindness would be utterly unknown. And if a unique person were finally born who saw green and blue differently, he would be looked upon as an oddity, as someone claiming to see differences where everyone agrees that no differences exist.
“Ha ha! Look at him. He has this silly notion that the grass and the sky are different colors.”
Then they would proceed to purchase some corrective lenses for him, which are tinted in such a way that the color of grass appears indistinguishable from the color of the sky. Thus the “deficiency” in his eyesight would be corrected, so that he could fit in as a normal member of society.
Of course, color blindness is not the only conceivable gap between perception and reality. All people in a given society may universally agree that a particular proposition is true, while in reality the proposition is false.
God’s grasp of reality is accurate. Regardless of what human society believes, we can check our fallible perceptions of reality against God’s perfect understanding of it. Let God be true, and every man a liar.
But if there is no God, then there is no ultimate way to verify whether our perceptions of reality are accurate or not.
It may be that grass and trees are two radically different colors, yet we call them both “green” because we are all color-blind.
It may be that deductive logic itself has a fatal flaw which makes it incoherent and inaccurate, but since all humans have a particular blindness in this area, we all mistakenly believe deductive logic to be very accurate and helpful.
Consider the color-blind people who created tinted glasses to “correct” the vision of the boy who thought the grass and the sky were different colors. It may be that we build all of our scientific instruments with a similar bias, “correcting” them in those cases where we “know” they previously had been giving us faulty readings.
If there is no God, then there is no adequate way out of the rabbit-hole. We may be able to verify universal human agreement regarding certain perceptions, but we are left with no way to know whether all humans are universally wrong on those certain points.
But if God does exist, and He created man in His own image, then it is reasonable to believe that God gave man an accurate sense of reason. If God created the human brain, then it is reasonable to believe that the human brain is able to do what it was designed to do. And even if that instrument should sometimes fail, it is reasonable to believe that God can provide the necessary corrections.
Thus all atheistic reasoning is stillborn, reducing itself to incoherence before it even gets started. Unless God created the human brain for the specific purpose of reasoning, there is no reason to believe that the human brain is able to reason accurately. It is reasonable to believe in the accuracy of human thought, only if we presuppose the existence of God.
Indeed, the teaching of the Church is that we are a world of people who have lost our senses. Our eyes may work fine, but our nous–the faculty with which humans sense and perceive the presence of God–has been crippled beyond recognition, and is desperately in need of healing.
“What’s a nous,” you say? “I’ve never heard of such a thing.”
There was another world where people asked similar questions:
“What’s the difference between the color of the grass, and the color of the sky? You say they are different? I’ve never heard of such a thing.”