In no way bound by guild rules and conventions or by rigid educational standards, Boyle was free to learn from whatever sources appealed to him. Repeatedly he emphasized the importance of learning from experience, both his own and that of others, and by "others" he included not only physicians and learned gentlemen, but even the meanest of society, provided they had experience in treating disease. This experience need not be restricted to treatment of humans but should include animals as well. Thus, in speaking of even the "skilfullest physicians," he indicated that many of them "might, without disparagement to their profession, do it an useful piece of service, if they would be pleased to collect and digest all the approved experiments and practices of the farriers, graziers, butchers, and the like, which the ancients did not despise...; and ... which might serve to illustrate the _methodus medendi_."[49] He was quite critical of physicians who were too conservative even to examine the claims of the nonprofessionals, especially those who were relatively low in the social or intellectual scale. This casts an interesting sidelight on the snobbishness of the medical profession. Boyle's willingness and ability to ignore the restrictions of an Establishment represent the full flowering of what I might call the Renaissance spirit--the drive to go outside accepted bounds, to explore, to _try_, to avoid commitment, and to investigate for oneself. What internal and external factors permit a successful breakaway from tradition? Rebels there have always been, yet successful rebels are relatively infrequent. The late seventeenth century was a period of successful rebellion, and the virtuosi were one of the factors which contributed to the success. Robert Boyle played a significant part in introducing new methods into science and new science into medicine.