A slate statue of Alan Turing in slate at Bletchley Park. The photograph on the wall in the background is also of Turing. Wikimedia, Jon CallasDuring World War II, Alan Turing and his Bletchley Park colleagues devoted countless hours to using rigorous deductive reasoning to decipher the military code associated with the Enigma machine. Their eventual success in cracking the German code allowed the Allies to eavesdrop on Nazi military communications, thereby changing the course of the war.
If they explicitly think about types of reasoning at all, biomedical scientists may subscribe to the view that deductive logic is primarily of value in mathematics. In this centenary year of his birth, it is appropriate to reflect on Turing’s profound and influential contributions, often dominated by deductive reasoning, not only to mathematical logic, but also to cryptography, computer science, and theoretical biology—and their relevance to the biomedical research enterprise.
Deductive logic is reasoning such that valid logical transformations applied to true premises guarantee the truth of any derived conclusions. For example, if all biomedical scientists are mortal, and Li is a biomedical scientist, then Li must be mortal. This form of argument contrasts with, for example, inductive reasoning, for which true assumptions and properly ...
