In spite of the very imperfect style in which he wrote, and the usually clumsy and often careless construction of his sentences, his works contain now and then noble thoughts expressed with simplicity and force.  “Natura est instrumentum Divinae operationis,” might be taken as the motto for his whole system of natural science.  In speaking of the value of words, he says,—­“Sed considerare debemus quod verba habent maximam potestatem, et omnia miracula facta a principio mundi fere facta sunt per verba.  Et opus animae rationalis praecipuum est verbum, et in quo maxime delectatur.”  In the “Opus Tertium,” at the point where he begins to give an abstract of his “Opus Majus,” he uses words which remind one of the famous “Franciscus de Verulamio sic cogitavit.”  He says,—­“Cogitavi quod intellectus humanus habet magnam debilitationem ex se....  Et ideo volui excludere errorum corde hominis impossible est ipsum videre veritatem.”  This is strikingly similar to Lord Bacon’s “errores qui invaluerunt, quique in aeternum invalituri sunt, alii post alios, si mens sibi permittatur.”  Such citations of passages remarkable for thought or for expression might be indefinitely extended, but we have space for only one more, in which the Friar attacks the vices of the Roman court with an energy that brings to mind the invectives of the greatest of his contemporaries.  “Curia Romana, quae solebat et debet regi sapientia Dei, nunc depravatur....  Laceratur enim illa sedes sacra fraudibus et dolis injustorum.  Pent justitia; pax omnis violatur; infinita scandala suscitantur.  Mores enim sequuntur ibidem perversissimi; regnat superbia, ardet avaritia, invidia corrodit singulos, luxuria diffamat totam illam curiam, gula in omnibus dominatur.”  It was not the charge of magic alone that brought Roger Bacon’s works into discredit with the Church, and caused a nail to be driven through their covers to keep the dangerous pages closed tightly within.

There is no reason to doubt that Bacon’s investigations led him to discoveries of essential value, but which for the most part died with him.  His active and piercing intellect, which employed itself on the most difficult subjects, which led him to the formation of a theory of tides, and brought him to see the need and with prophetic anticipation to point out the means of a reformation of the calendar, enabled him to discover many of what were then called the Secrets of Nature.  The popular belief that he was the inventor of gunpowder had its origin in two passages in his treatise “On the Secret Works of Art and Nature, and on the Nullity of Magic,"[37] in one of which he describes some of its qualities, while in the other he apparently conceals its composition under an enigma.[38] He had made experiments with Greek fire and the magnet; he had constructed burning-glasses, and lenses of various power; and had practised with multiplying-mirrors, and with mirrors that magnified and diminished.  It was no wonder that a man who knew and employed such wonderful things, who was known, too, to have sought for artificial gold, should gain the reputation of a wizard, and that his books should be looked upon with suspicion.  As he himself says,—­“Many books are esteemed magic, which are not so, but contain the dignity of knowledge.”  And he adds,—­“For, as it is unworthy and unlawful for a wise man to deal with magic, so it is superfluous and unnecessary."[39]