ROGER BACON
Roger Bacon is one of the persons who first laid stress on the importance of science and in particular of experimentation. He had free-thinking attitudes; as a result he got into trouble with authorities, as it is the case in all ages of history, and put into prison for 14 years. He wrote on geography, alchemy, mathematics and many other things. He said one could learn many things from the heathen. In his work Opus Majus he said there were four causes of ignorance: 1- Appeals to an unsuited authority 2- The undue influence of custom 3- Opinions of the unlearned crowd 4- Wisdom displays which are simply covered up ignorance