Gorgias the Nihilist, an ancient Greek philosopher, was said to have argued the following four points:

1. Nothing exists;
2. Even if something exists, nothing can be known about it; and
3. Even if something can be known about it, knowledge about it can’t be communicated to others.
4. Even if it can be communicated, it cannot be understood.

Of course, if you can understand his argument, he’s wrong. So too, many modern thinkers hold to positions that, fall apart into self-refutation when critically examined.

Today, I want to look at three such popular claims. In showing their inherent contradictions, I hope to show why we can (and must) affirm that knowable, non-empirically testable, absolute truths exist.

Step 1: Answering Relativism

The claim: “Absolute truth does not exist.”

Why it’s self-refuting: The claim “absolute truth does not exist” is either absolutely true or it’s not. But, of course, it can’t be absolutely true, since that would create a contradiction: we would have proven the existence of an absolute truth, the claim itself. Since it cannot be absolutely true, we must concede that there are some cases in which the proposition “absolute truth does not exist” must be false… in which case, we’re back to affirming the existence of absolute truth.

What we can know: Absolute truth exists. Put another way, the claim “absolute truth exists” is absolutely true.

Step 2: Answering Skepticism

The claim: “We can’t know anything for certain.” Or “I don’t know if we can know anything for certain.”

Why it’s self-refuting: This one is a subtler self-refutation then the first, because it looks humble. After all, if I can say, “I don’t know the number of stars in the universe,” why can’t I take it a few steps further, and say, “I can’t know anything for certain”?

Simple. Because in saying that, you’re claiming to know something about your own knowledge. When we say, “I don’t know x,” we’re saying, “I know that my knowledge on x is inconclusive.”

Take the most mild-seeming statement: “I don’t know if we can know anything for certain.” What you’re really saying is that, “I know that my knowledge on whether anything can be known for certain is inconclusive.” So you’re still affirming something: that you know your knowledge to be inconclusive.

There are two ways of showing this. First, because it could be a lie. The claim “I don’t know who took the last cookie,” could very well be proven false, if we later found the cookie in your purse. So these “I don’t know” claims are still affirming something, even if they’re just affirming ignorance.

Second, apply the “I don’t know” to another person. If I said, “You don’t know anything about cars,” I’m making a definitive statement about what you do and don’t know. To be able to make that statement, I have to have some knowledge about you and about cars. So if I was to say, “you don’t know if we can know anything for certain,” I’d be claiming to know that you were a skeptic – a fact that I can’t know, since I’m not sure who’s reading this right now.

So when you say “I don’t know if we can know anything for certain,” you’re saying that you know for certain that you’re ignorant on the matter. But that establishes that things necessarily can be known for certain.

This is unavoidable: to make a claim, you’re claiming to know something. So any positive formulation of skepticism (“no one can know anything for certain,” “I can’t know anything for certain,” “I don’t know anything for certain,” etc.) ends up being self-refuting. For this reason, the cleverest skeptics often word their skepticism as rhetorical questions (e.g., de Montaigne’s “What do I know?”). If they were to say what they’re hinting at, it would be self-refuting. They avoid it by merely suggesting the self-refuting proposition.

Finally, remember that in Step 1 we determined that the claim “absolute truth exists” is absolutely true. We’ve established this by showing the logical contradiction of holding the contrary position. In other words, we’ve already identified a truth that we can know for certain: “absolute truth exists.”

What we can know: Absolute truth exists, and is knowable.

Step 3: Answering Scientific Materialism

The claim: “All truth is empirically or scientifically testable.”

Why it’s self-refuting: The claim that “All truth is empirically or scientifically testable” is not empirically or scientifically testable. It’s not even conceivable to scientifically test a hypothesis about the truths of non-scientifically testable hypotheses. In fact, “all truth is empirically or scientifically testable” is a broad (self-refuting) metaphysical and epistemological claim.

What about the seemingly moderate claim, “We cannot know if anything is true outside of the natural sciences”? Remember, from Step 2, that “I don’t know x,” means the same as saying, “I know that my knowledge on x is inconclusive.” Here, it means, “I know that my knowledge on the truth of things outside of the natural sciences is inconclusive.” But the natural sciences can never establish your ignorance of truths outside the natural sciences. So to make this claim, you need to affirm as certain a truth that you could not have derived from the natural sciences. So even this more moderate-seeming claim is self-refuting.

Furthermore, all scientific knowledge is built upon a bed of metaphysical propositions (for example, the principle of noncontradiction) that cannot be established scientifically. Get rid of these, and you get rid of the basis for every natural science. There’s no way of rejecting these premises while still affirming the conclusions that the natural sciences produce.

Finally, remember that in Step 2, we established the truth of the claim “absolute truth exists, and is knowable.” This is a truth we know with certainty, but it’s not an empirical or scientific question. It can be established simply by seeing that its negation is a contradiction. So that’s a concrete example of an absolute truth known apart from the empirical and scientific testing of the natural sciences.

Conclusion: There exists absolute and knowable truth, outside of the realm of the natural sciences, and not subject to empirical and scientific testing.

The presence of our enhanced human consciousness not only differentiates humans from animals, it also aids in making the case for the existence of God. That’s because through our human consciousness we desire five transcendental experiences, none of which are necessary for survival. These five transcendental desires are our yearning for: (1) perfect knowledge/truth, (2) perfect love, (3) perfect justice/goodness, (4) perfect beauty, and (5) perfect home/being.

Most interestingly, any earthly satisfaction of these five inner desires leaves us feeling frustrated and wanting more. That’s because what we desire is a perfect experience of each of these five transcendental desires. But, since perfect knowledge/truth, perfect love, perfect justice/goodness, perfect beauty, and perfect home/being don’t exist here on earth, why do we seek them? It makes no sense for us to seek that which is unattainable. We only seek that which is attainable, if not here then in the hereafter.

What we seek is something transcendental, something beyond our world and beyond our earthly experience. What we seek is God, who is the Perfect Knowledge/Truth, Perfect Love, Perfect Justice/Goodness, Perfect Beauty, and Perfect Home/Being. For as St. Augustine of Hippo wrote nearly 1,600 years ago, “Thou hast made us for Thyself and our hearts are restless until they rest in Thee.”

Priest, philosopher, and theologian Fr. Robert J. Spitzer, S.J., Ph.D., has written several books about how our ultimately unfulfilled yearning for these five transcendental experiences provides evidence of the existence of God. Let’s take a closer look at each of these five transcendental desires found within the human condition and how they reveal God's existence.

(1) Desire for Perfect Knowledge/Truth

Even in young children, we find a desire for perfect knowledge when they ask “Why is that?” and when given an answer they then ask the next question, “Well, why is that?” It seems this questioning would go on forever, at least until an adult brings it to an end! This process reveals that children (indeed, all of us) recognize the inadequacy of a partial answer, and that true satisfaction will occur only when a complete and perfect understanding has been achieved.

Humans do not seek just practical knowledge (e.g., “How do I get the food I need to survive?”). Rather, we want to know just for the sake of knowing, and we have an innate desire for a full and complete explanation. This is evident in the ongoing work of science in seeking a more complete understanding of our world. We know we have not yet reached a perfect understanding of our world, so we research and seek more knowledge, more truth.

Interestingly, we know our knowledge is not complete. If we did not know it was incomplete, we would not keep asking additional questions. It is our awareness that there is more to be known at the very moment when something is known which drives us to additional questioning. We have an awareness of the more.

The issue then arises: Why do we continue asking questions every time something is understood, as if we intuitively know that our current knowledge is limited and does not meet our desire to know all that is to be known? How can we be aware of something beyond everything we currently understand? Why do we have an awareness that what we now know is only a partially complete answer?

This intuitive awareness that there is more to be known than what we now know seems to defy a naturalistic explanation. All our knowledge is incomplete and we know it. But why are we aware that there is more to be known beyond what we currently know?

It seems the best explanation is that our conscious desire for perfect knowledge and complete truth has been written in our human nature by God, who is the Perfect Knowledge and Perfect Truth that we seek. This awareness of the more reveals the presence of God to human consciousness and grounds the belief in human transcendentality (the presence of our soul).

(2) Desire for Perfect Love

We humans also have a desire for perfect and unconditional love. However, this desire can mislead us into expecting perfect love from another human being. When the relationship does not fulfill our desire for perfect love, this expectation leads to frustration and quite possibly to a decline in the relationship. For example, as the imperfections in the love of our beloved manifest themselves (e.g., our spouse is not perfectly understanding, kind, forgiving, self-giving, and concerned for me and all my interests), we at first become irritated. This irritation often leads to frustration, which in turn becomes dashed expectations. These dashed expectations may become either quiet hurt or overt demands, both aimed at extracting a more perfect love from our beloved. When this perfect love does not happen, thoughts of terminating the relationship may arise.

Why do we fall prey to such an obvious error? Because our desire is for love to be perfect and unconditional, but the reality is otherwise. We humans just cannot satisfy each other’s desire for perfect and unconditional love, no matter how hard we try. Thus, our dissatisfaction and frustration arise out of a conscious desire for a perfect love, a love that cannot be experienced in our relationships with others here on earth.

But what is the origin of our deep desire and yearning for perfect love? Why would we have this desire for perfect love, especially as it just leaves us feeling dissatisfied and frustrated when we cannot find it with another person? Why do we have an awareness of and desire for a type of love that we have neither known nor will experience from another human being?

It seems we are searching for perfect love in all the wrong places. Our desire for perfect and unconditional love can only be met by the Perfect Love (God). Again, we find that God has implanted in each of us a conscious desire for a perfect love that only God can fulfill.

(3) Desire for Perfect Justice/Goodness

In addition, we have a conscious desire for perfect justice and goodness. For example, even in young children an imperfect expression of justice from their parents will elicit the immediate response, “That’s not fair!” Adults do the same thing. We feel the same outrage toward groups, social structures, and even God when we perceive that we have not been treated fairly. We truly expect that perfect justice ought to happen, and when it doesn’t we feel a profound and deep outrage. We expect more justice and goodness than our finite world can deliver, and this causes outrage and cynicism when it does not come to pass.

Once more, what could be the source of our desire for perfect justice and goodness, especially when it seems well beyond the actual justice and goodness we can possibly experience? Given that our desire for perfect justice/goodness cannot be found in an imperfect world, it seems that its origin is from perfect Justice/Goodness itself. For this reason, philosophers have associated this notion of perfect Justice/Goodness with the presence of God to human consciousness.

(4) Desire for Perfect Beauty

Once in a great while, we think we have found perfect beauty. This might occur while looking at a scene of wonderful natural beauty: a magnificent red sunset over the water or majestic snowcapped mountains against a horizon of blue sky. Yet, even then, we get bored and strive for an even more perfect manifestation of natural beauty--a little better sunset, another vantage point of the mountains that’s a little more perfect.

As with the other transcendentals, we seem to have an innate awareness of what is most beautiful. This incites us to desire a perfectly beautiful ideal, which leads to both positive and negative results. The positive result is the continuous human striving for artistic, musical, and literary perfection. This striving has left a magnificent cultural legacy of architecture, art, music, drama, etc. However, the negative effect is that we grow bored or frustrated with any imperfect manifestation of beauty. For example, a flowering garden can achieve a certain degree of beauty. But our continued desire to improve it only makes us feel dissatisfied when we cannot perfect it indefinitely.

As with the other transcendentals, we are innately aware of and attracted to perfect beauty itself. But where does our conscious sense of perfect beauty (which does not even exist in our world) come from? Since it seems that the notion of perfect Beauty cannot be obtained from a world of imperfect beauty, we are led to the realization that its’ origin arises out of perfect Beauty itself. For this reason, philosophers have associated this notion of perfect beauty with the presence of perfect Beauty (i.e., God) to human consciousness.

(5) Desire for Perfect Home/Being

The fifth transcendental is our desire to be at perfect harmony and peace in our being and in our world. When our desire for perfect home is even partially fulfilled, theologians, saints, and mystics throughout the ages have referred to this as joy, love, awe, unity, holiness, and/or peace. Again, we need to ask what gives rise to our desire for perfect harmony and our yearning to feel comfortably at home in our world? Once more, the origin of this awareness seems to be traceable to the perfect Home itself. For this reason, philosophers and theologians have associated our desire for a perfect home with the presence of God to human consciousness.

In summary, we find evidence of God’s existence in our desire for these five transcendental experiences. Our yearning for “more” leave us with an emptiness that only God can fill. For as C.S. Lewis stated in Mere Christianity, “Creatures are not born with desires unless satisfaction for those desires exists. A baby feels hunger: well, there is such a thing as food... If I find in myself a desire which no experience in this world can satisfy, the most probable explanation is that I was made for another world.”

God is perfect and wants us to be one with Him. Thus, our inner craving for perfection must come from and is directed towards God alone. As the Catechism of the Catholic Church (#27) states, “The desire for God is written in the human heart, because man is created by God and for God; and God never ceases to draw man to himself. Only in God will he find the truth and happiness he never stops searching for.”