The Science of Conjecture: Evidence and Probability Before Pascal

by James Franklin

Much has been written on the status of scientific theories in the century of the scientific revolution. The most prominent fact is that the leading writers—Bacon, Galileo, Descartes, and Newton—stated emphatically that their results were certain. Their statements were undoubtedly sincere, but one should not be too quick to conclude that the science of the time was universally thought to be a search for certainty. It is proverbial that very successful people tend to possess, besides unlimited energy, an utter conviction that their own opinions are right. There is less talk about certainty in the lesser, but still exceptionally brilliant, scientists of the seventeenth century. There is also less insistence on certainty in some of the works of the great men themselves, in places where they stopped advertising their projects and dealt with the detailed business of explaining their results.