It was, indeed, on this principle of the close interconnection of all branches of knowledge that Bacon based his plea and his scheme of reform.  And the idea of the “solidarity” of the sciences, in which he anticipated a later age, is one of his two chief claims to be remembered. [Footnote:  Cp.  Opus Tertium, c. iv. p. 18, omnes scientiae sunt connexae et mutuis se fovent auxiliis sicut partes ejusdem totius, quarum quaelibet opus suum peragit non solum propter se sed pro aliis.] It is the motif of the Opus Majus, and it would have been more fully elaborated if he had lived to complete the encyclopaedic work, Scriptum Principale, which he had only begun before his death.  His other title to fame is well-known.  He realised, as no man had done before him, the importance of the experimental method in investigating the secrets of nature, and was an almost solitary pioneer in the paths to which his greater namesake, more than three hundred years later, was to invite the attention of the world.

But, although Roger Bacon was inspired by these enlightened ideas, although he cast off many of the prejudices of his time and boldly revolted against the tyranny of the prevailing scholastic philosophy, he was nevertheless in other respects a child of his age and could not disencumber himself of the current medieval conception of the universe.  His general view of the course of human history was not materially different from that of St. Augustine.  When he says that the practical object of all knowledge is to assure the safety of the human race, he explains this to mean “things which lead to felicity in the next life.” [Footnote:  Opus Majus, vii. p. 366.]

It is pertinent to observe that he not only shared in the belief in astrology, which was then universal, but considered it one of the most important parts of “mathematics.”  It was looked upon with disfavour by the Church as a dangerous study; Bacon defended its use in the interests of the Church itself.  He maintained, like Thomas Aquinas, the physiological influence of the celestial bodies, and regarded the planets as signs telling us what God has decreed from eternity to come to pass either by natural processes or by acts of human will or directly at his own good pleasure.  Deluges, plagues, and earthquakes were capable of being predicted; political and religious revolutions were set in the starry rubric.  The existence of six principal religions was determined by the combinations of Jupiter with the other six planets.  Bacon seriously expected the extinction of the Mohammedan religion before the end of the thirteenth century, on the ground of a prediction by an Arab astrologer. [Footnote:  Ib. iv. p. 266; vii. p. 389.]