The week before Christmas is a good time of year to write about miracles because it’s a time to be reminded of the meaningfulness of miracles. But what about their truth? Doesn’t the uniformity of nature make miracles impossible?
Thomas Aquinas said a miracle is ‘beyond the order commonly observed in nature’ (Summa Contra Gentiles III), but David Hume went further and defined a miracle as ‘a violation of the laws of nature’ (Of Miracles, 1748). Hume also claimed that scientific induction required the uniformity of nature, so on his telling, miracles undermined science.
However, Hume failed to establish the uniformity of nature on rational grounds. The future does not necessarily resemble the past. The most he could say was that the uniformity of nature is a matter of custom and habit. (There’s a convenient summary of his argument here: Probable reasoning has no rational basis.)
Others have also been unable to establish the uniformity of nature on rational grounds. This failure led to Karl Popper’s argument that induction is merely not untrue, and that one counterexample can falsify any induction. However, the history of science shows an unwillingness to abandon well-accepted science because of one or a few anomalies.
Does scientific induction really require the uniformity of nature? No, that is a misunderstanding of science that goes back to Scholasticism, which was revived in the 19th century by Richard Whately and John Stuart Mill. See John P. McCaskey’s writings on The History of Induction.
Induction is based on classification, not a principle of uniformity. Observation and experiment lead to the definition of a class by a uniformity. Then by definition other objects or events in the same class possess the same uniformity, whether in the past, present, or future. As I wrote here, science studies uniformity but that is far from requiring uniformity everywhere at all times.
It is better to define a miracle by what it is – unique – rather than what it is not – uniform. A miracle is a highly unique event or result, especially one attributed to divine agency. Since science studies uniformity, not uniqueness, it doesn’t have much to contribute about miracles. But uniqueness is studied by other disciplines such as history, philosophy, theology, and literature – that is, the humanities, not the sciences.
Miracles are by their nature very unique and significant. They fall outside of uniformity but since there is no valid principle of uniformity, that is not a problem.