I. EVIDENCE AGAINST AUTHENTICITY OF THE SHROUD OF TURIN
Robert Drews (In Search of the Shroud of Turin: New Light on Its History and Origins, 1984) gives a lot of evidence that Gnostics created the Shroud of Turin in the 1st or 2nd century using a crucified victim or volunteer and methods that have been lost to history. Thomas De Wesselow (The Sign: The Shroud of Turin and the Secret of the Resurrection, 2012) and John Loken (The Shroud Was the Resurrection: The Body Theft, the Shroud in the Tomb, and the Image that Inspired a Myth, 2006) give evidence that the image on the Shroud of Turin was created mysteriously while it covered the crucified body of Jesus. Many people judge the Holy Shroud to be authentic even though images are always created by human beings and no one has been able to explain how a corpse could produce such a detailed blood-stained image on that large piece of linen. Loken and De Wesselow, by the way, are using the authenticity of the Shroud to give an historical explanation for the Resurrection of Jesus.
II. STRUCTURE OF THE HUMAN MIND
There are five different methods of inquiry that are involved in the study of the Shroud of Turin: science, metaphysics, theology, history, and philosophy. These methods of inquiry are rooted in the structure of the human mind and in the types of questions human beings ask.
The scientific method is the result of a philosophical inquiry and reflects the way the human mind is structured. At the lowest level are observations, which require paying attention. At the level of inquiry, humans ask questions about their observations. Humans want to know the cause of things, the relationship between things, and the unity between things. Extremely intelligent humans invent theories or hypotheses to answer these questions. At the level of reflective judgment, humans marshal the evidence and decide whether a theory is true or just probable. This level requires being rational. The fourth level is deciding what to do with our bodies, which requires being responsible.
III. METAPHYSICS, SCIENCE, PHILOSOPHY, AND THEOLOGY
This is an example of a scientific question: Why is the sky blue? A metaphysical question is: What is knowing the sky is blue? Knowing the color of something means more than that light is entering your eye and a signal is going to your brain. It means an awareness of this. Scientific questions arise from observations made with our senses. Metaphysical questions arise from our ability to transcend ourselves and make ourselves the subject of our own knowledge. The question about awareness is equivalent to: What is the conscious knowledge of humans as opposed to the sense knowledge of animals? The theory or answer supported by the evidence and judged to be true by rational people is that it is a mystery. This can be expressed by saying humans are embodied spirits or that the human soul (form) is spiritual. We can comprehend what a human being is because we know everything we do and everything that happens to us. But, we can't explicate or define what a human being is.
Many people confuse metaphysics with philosophy. Philosophy is a method of inquiry that transcends a more fundamental method of inquiry. Historiography and the scientific method are both examples of philosophy because they are above history and science.
In metaphysics, finite beings exist because humans have free will. Free will means we possess a center of action that unifies us with respect to ourselves and makes us different from other human beings. A finite being is a composition of essence and existence, and an infinite being is a pure act of existence. In Western religions, we call the infinite being God. Theology is the study of God's revelation to mankind through the prophetic religions of the Near East, the mystical religions of India, and the wisdom religions of China. Theology involves a different kind of knowledge than metaphysics, science, or history. The knowledge of theology is called faith and the knowledge of the other three methods of inquiry is called reason.
IV. THE BIG BANG
Faith, science, and metaphysics are intertwined by the discovery of cosmic background radiation in the 1960s. In the 1920s, it was observed that the universe was expanding and physicists asked why. An astronomer, who happened to be a Catholic priest, invented the theory that the universe began to exist 14 billion years ago and was once smaller than a grain of salt. I am using this phrase not to ridicule the theory, but because of a calculation I did using the size of a grain of salt. The universe consists of hundreds of billions of galaxies with hundreds of billions of stars each. The density of the universe is small because all this mass is distributed over a large volume. If you compress Earth into a volume the size of a grain of salt, the density becomes 7×1029 times greater than its real density of 5.5 grams per cubic centimeter. If you compress all of the galaxies into a sphere the size of Earth, you increase the density by a similar amount. (I assumed the volume of a grain of salt is 1.5 cubic millimeters, and the universe is a sphere with a radius of 14 billion light years. For the mass of the universe, I assumed it is equivalent to the mass of 10 to the 21st power of suns).
Five hundred thousand years after our known universe began existing, electrons and protons formed hydrogen atoms and emitted photons with a specific energy. This is the radiation that was discovered in the 1960s. Scientists now judge the theory of the Big Bang, as it was derisively called, to be true.
Many people consider the Big Bang evidence of God's existence. This is not consistent with the cosmological argument, which is based on the assumption or hope that the universe is intelligible and the insight that a finite being needs a cause. My understanding is that the Big Bang is evidence that the universe is not intelligible which means it is evidence that God does not exist.
However, the Big Bang is an object of study in theology because the Bible says God created the universe from nothing. This is a reason to believe God inspired the human authors of the Bible because the human writers knew nothing about the expanding universe. It is not evidence for revelation because evidence is part of science, metaphysics, and history. Instead of evidence, theology has reasons to believe and signs. We can see the truth of the metaphysical proposition that God exists just as we can understand why the sky is blue. We can criticize the judgment, intelligence, and knowledge of people who deny or don't admit metaphysics leads to God's existence or don't know that density fluctuations, not molecules, cause the sky to be blue. We can't criticize the judgment of those who do not believe the Bible is the word of God. In faith, we know something is true because God is telling us. In reason, we know something is true because we can see the truth of it. Faith is both a decision and a gift from God.
History and Science
Scientists ask questions about things that exist. Historians ask questions about past events, which only exist in the minds of historians. There are different criteria for deciding which questions scientists and historians should to try to answer. For example, it is an historical fact that Jesus was a healer and exorcist who did not charge for his services. This raises the question: Did Jesus heal anyone? However, this is not a good historical question because there are no before and after x-rays and other medical records from the 1st century.
The Shroud of Turin, on the other hand, is an artifact. It actually exists, and the question of how the image was created cannot be dismissed as not being a good scientific question. It is just like the question: What caused the Big Bang? In both cases, scientists should do their best to come up with a hypothesis.