Until the 13th century the philosophical doctrine of apriorism was applied without contemplation, and if the result of any experiment or observation conflicts with an accepted theory, the experiment or observation had to be bad or was the product of a diabolical influence. Nowadays apriorism is not accepted in research, thanks to the work of monk Francis Bacon who gave the basis of the methodology used today called the Scientific Method that points out that knowledge is obtained through a joint work of observations, experiments and good judgment.