Skepticism and Faith

Rational Responses to Skepticism is not a book for everyone. If one expects it to be another apologetics book filled with historical and scriptural analysis, he is badly mistaken. Rather, this volume is a rigorous rational defense of the intellectual foundations for Christianity in general and of Catholicism in particular.

[For those who cannot access Rumble, here is another link].

Following Vatican Council II, most of the previously orthodox Catholic colleges and universities slowly abandoned their firm commitment to the Catholic intellectual heritage, especially by decreasing both the number and traditional content of required theology and philosophy courses – and even by changing theology courses into what they called “religious studies.” This tendency was especially evident in their failure to continue to teach the Thomistic philosophical sciences, such as logic, philosophical psychology, metaphysics, natural theology, and natural law ethics. Such courses were routinely replaced by far fewer ones, which were then taught using an historical method inherently inimical to the truth status of competing historical positions. This, in turn, has led to generations of otherwise educated Catholic college graduates who have little or no real understanding of the Church’s intellectual heritage, and especially, its unequalled contributions offered by the philosophy of St. Thomas Aquinas.

Rational Responses to Skepticism’s intended mission is to restore significant respect for that all-important Catholic intellectual tradition. Since it is a compilation of forty-one separate essays – each one intended to be read on its own, it is not a daunting challenge to read for most educated persons. But, it contains rigorous intellectual defenses of foundational truths essential to authentic religious revelation, that is, to Christianity, and specifically, to Catholicism.

The book contains sections refuting scientific materialism and proving man’s spiritual nature. It gives a rigorous explanation of basic intellectual certitudes, such as the metaphysical first principles of being and causality. From these it proceeds to prove God’s existence and properties as well as addressing the problem of evil and the objective foundation for a natural law ethics whose authority is God himself. Finally, it examines the rational truths underlying religious revelation, including the scientific possibility of a literal Adam and Eve, a unique exposition of the demonstrable miracles of Fatima, and even an explanation as to why the possible existence of space aliens does not disturb any of the preceding objectively demonstrated truths.

As an example of the kind of content found in this volume, I will now present a brief summary of its first chapter, so that the reader can judge for himself the book’s value as a substantive resource for answering the skepticism and confusion which is the hallmark of the present age.

The first chapter of my book, Rational Responses to Skepticism (2022), is entitled “Naturalism’s Epistemological Nightmare.”

The purpose here is simply to give some indication as to the content of that chapter – the full content of which is found in the book itself.

There are many who think that there are only two types of knowledge: (1) that based on religious faith, and (2) that based on scientific knowledge. Effectively, this makes natural science sound like the only really rational basis for truth, while things, like the Bible, are followed without any real rational proof. No room is left for anything like having rational foundations for religion. You can be religious or you can be rational and scientific. But, you cannot be both. The classical philosophical foundations for religious faith are overlooked in this all too prevalent mindset.

Materialism is the view that all that exists somehow extends in time and space, whether in the form of subatomic particles or waves. Naturalism claims that all that exists can be known by empirical verification – thus excluding supernatural entities, such as the God of classical theism. Essentially, they amount to the same thing.

The problem with naturalism which I now consider lies in its epistemology, that is, the science that considers whether and how true knowledge is possible. According to naturalism, all that is real is found in physical reality. Natural science studies that reality from the immense reaches of the limits of outer space down to the incredibly small physical entities of subatomic particles and waves.

But, the method of natural science presupposes observation of the physical world.

We observe with our eyes light from the farthest stars and galaxies, some 13.8 light years distant. We call such distance measurements, “light years,” since it take a year for light to travel some 5.8 trillion miles to reach our eyes. That is why we say we are looking back in time when we look at distant stars. What we really see is not the star as it appears in the universe at this moment in time, but rather, as it appeared many years in the past. What we really are seeing is merely the light from that distant – possibly long extinct star – as that light now strikes our eyes.

But, wait! It turns out that that light we see strikes the outer eye only to pass through its lens and reaches the retina at the back of the eye. Yet, the retina, in turn, does not end the process, but rather, sends a nerve impulse through the optic nerve to the back of the brain, what is called the occipital lobe. As a result, science says an image is formed in the back of the brain – and that is what we really are “seeing,” when we see that distant star! So it is with every external object of sight. All we are really seeing according to this scientific reasoning is images formed in the back of the brain through a chain of causality starting with the external object, but ending deep within the brain itself, where “images” of external objects are actually experienced by us.

If this “scientific” explanation of vision is correct, then the truth is that we never see external objects at all. Rather, all we really know is internal images of things which we experience as external to us, but which are really merely internal brain representations we hope accurately depict external reality.

And yet, the whole story of science is allegedly the discovery of the nature of physical objects in a real material world external to our bodies – a world in which our bodies are but the least infinitesimal piece of a cosmos claimed to be about 93 billion light-years in diameter!

All this means that, while natural science claims to take its observations from external things in the physical world, the logic of its own explanation for visual experience leads to the paradoxical conclusion that we never really experience that physical world at all. We actually experience only events taking place inside our heads!

This absurd conclusion is forced, not by natural science itself, but by trying to think the content of that science in terms of purely physical things. Physical things are extended in space. This forces any explanation of seeing into a causal-chain straight jacket in which external objects must be traced in their effects to changes inside the body which, by definition, are distinct from and other than the objects we think we observe scientifically.

The simple fact is that we would not even know we have a brain or inside of our heads except that someone has done anatomical dissections of the head and found the brain. But, to do that we must accurately observe external objects. Yet, our scientific analysis leads us to the contradictory conclusion that we actually are not seeing the head or brain themselves, but only an “image” of such organs deep inside the “unseen” brain itself!

In philosophical terms, the view that we directly know external reality itself is what is called “epistemological realism.” But, if all we claim to know are solely images or ideas of things inside our heads or brains, that is called “epistemological idealism,” since only the idea or representation of the thing is known, not the thing itself.

As seen above, this paradoxical or contradictory situation arises, not because of our actual experience (which is one of seeing the external world itself), but because of a complicated analysis made in terms of physical mechanisms, such as light beams, eyes, optic nerves, and insides of brains.

But, unless we can actually make physical observations of external things themselves, natural science is impossible, since that is its very method!

This absurd result arises from trying to explain the whole process of vision in purely physical terms, as if nothing exists but physical mechanisms. The bottom line is that the philosophy of materialism leads to absurd conclusions. Therefore, materialism must be a false belief. But, if materialism is false, then non-material entities must exist. Somehow, sense perception of the external world requires the use of powers that are not mere mechanisms of physical things, that is, of things extended in space.

Because this self-contradictory line of reasoning arises as a direct result of the assumption that everything is physically extended in space, it must be that something non-material — something not extended in physical space — must exist.

In a word, the validity of natural science itself requires first that one cannot be a philosophical materialist. Otherwise, natural science entails that we cannot know the external physical world which it allegedly uses as the subject matter of scientific observation and inferences. Materialism or naturalism leads its own much-beloved natural science into an epistemological nightmare!

Later chapters of Rational Responses to Skepticism explain more exactly just how non-material sensory powers and other non-material realities must exist and play a central role in our understanding of the true nature of the world in which we live. The foregoing is simply a sample of the kind of reasoning one may expect in the entire volume – a volume that contains rigorous defenses of central portions of the entire Catholic intellectual tradition. My hope is that this book may serve as a valued reference volume for most well-educated Catholics as well as Catholic university philosophical and theological faculty and students.


Dr. Dennis Bonnette retired as a Full Professor of Philosophy in 2003 from Niagara University in Lewiston, New York, where he also served as Chairman of the Philosophy Department from 1992 to 2002. He received his doctorate in philosophy from the University of Notre Dame in 1970. He is the author of three books, Aquinas’ Proofs for God’s ExistenceOrigin of the Human Species, and Rational Responses to Skepticism: A Catholic Philosopher Defends Intellectual Foundations for Traditional Beliefas well as many scholarly articles.


Featured: The Allegory of the Faith, by Johannes Vermeer; painted ca. 1670.