 Some natural philosophers believed that scientific knowledge was little more than the proper application of observational and experimental techniques on natural phenomena. Francis Bacon went so far as to claim that it was possible to perform what he called a crucial experiment (experimentum crucis), an ideal experiment of sorts that can determine alone which of two rival hypotheses is correct. And even some of the giants of modern science such as Newton subscribed to the view that scientific theories are directly induced from experimental results and observations without the help of untested hypotheses. It is little wonder, then, that many natural philosophers thought that experimental techniques and their proper application should be a primary object of philosophical study of science.