By the way, it is no rebuttal to Hume to say, “Admittedly, scientific laws are not 100 percent true, but at least they are 99.9 percent true. They may not be certain, but they are very likely to be true.” How would you go about verifying this statement? How would you establish the likelihood, for instance, of Newton’s inverse square law? It says that every physical object in the universe attracts every other physical object with a force directly proportional to their masses and inversely proportional to the square of the distance between them. This law cannot be tested except by actually measuring the relationships between all objects in the universe. And as that is impossible, no finite number of tries can generate any conclusion about how probable Newton’s statement is. Ten million tries cannot establish 99.9 percent probability—or even 50 percent probability—because there may be twenty million cases that haven’t been tried where Newton’s law may be found inadequate.
At this point we should pause to consider astronomer Neil deGrasse Tyson’s exasperated outburst. Tyson believes it is simply ridiculous to say that scientific laws are not reliable: “Science’s big- time success rests on the fact that it works.” If science did not accurately describe the world, then airplanes would not fly and people who undergo medical treatments would not be cured. Airplanes do fly and sick people are healed in the hospital, and on that basis science must be taken as true. Better to fly in an airplane constructed by the laws of physics, Tyson scornfully says, than to board one “constructed by the rules of Vedic astrology.”I agree that science works—and you won’t get any argument from me about the limits of Vedic astrology—but it doesn’t follow that scientific laws are known to be true in all cases. Consider this dismaying realization. Newton’s laws were for nearly two centuries regarded as absolutely true. They worked incredibly well. Indeed, no body of general statements had ever been subjected to so much empirical verification. Every machine incorporated its principles, and the entire Industrial Revolution was based on Newtonian physics and Newtonian mechanics. Newton was vindicated millions of times a day, and his theories led to unprecedented material success. Yet Einstein’s theories of relativity contradicted Newton, and despite their incalculable quantity of empirical verification, Newton’s laws were proven in important ways to be wrong or at least inadequate. This does not mean that Einstein’s laws are absolutely true; in the future they too might be shown to be erroneous in certain respects.
From such examples philosopher Karl Popper concluded that no scientific law can, in a positive sense, claim to prove anything at all. Science cannot verify theories, it can merely falsify them. When we have subjected a theory to expansive testing, and it has not been falsified, we can provisionally believe it to be true. This is not, however, because the theory has been proven, or even because it is likely to be true. Rather, we proceed in this way because, practically speaking, we don’t have a better way to proceed. We give a theory the benefit of the doubt until we find out otherwise. There is nothing wrong in all this as long as we realize that scientific laws are not “laws of nature.” They are human laws, and they represent a form of best-guessing about the world. What we call laws are nothing more than observed patterns and sequences. We think the world works in this way until future experience proves the contrary.
I am laying out the skeptical case here not because I want to endorse without reservations Hume’s (or Popper’s) philosophy. Rather, my goal is to overthrow Hume’s argument against miracles using his own empirical and skeptical philosophy. Hume insists that miracles violate the known laws of nature, but I say that Hume’s own skeptical philosophy has shown that there are no known laws of nature. Miracles can be dismissed only if scientific laws are necessarily true—if they admit of no exceptions. But Hume has demonstrated that for no empirical proposition whatsoever do we know this to be the case. Miracles can be deemed unscientific only if our knowledge of causation is so extensive that we can confidently dismiss divine causation. From Hume we learn how limited is our knowledge of causation, and therefore we cannot write off the possibility of divine causation in exceptional cases.
