Nature, and of the powers thereof.  For when the authority of great names has reigned unquestioned for many centuries, those names become, to the human mind, integral and necessary parts of Nature itself.  They are, as it were, absorbed into it; they become its laws, its canons, its demiurges, and guardian spirits; their words become regarded as actual facts; in one word, they become a superstition, and are feared as parts of the vast unknown; and to deny what they have said is, in the minds of the many, not merely to fly in the face of reverent wisdom, but to fly in the face of facts.  During a great part of the middle ages, for instance, it was impossible for an educated man to think of Nature itself, without thinking first of what Aristotle had said of her.  Aristotle’s dicta were Nature; and when Benedetti, at Venice, opposed in 1585 Aristotle’s opinions on violent and natural motion, there were hundreds, perhaps, in the universities of Europe—­as there certainly were in the days of the immortal ’Epistolae Obscurorum Virorum’—­who were ready, in spite of all Benedetti’s professed reverence for Aristotle, to accuse him of outraging not only the father of philosophy, but Nature itself and its palpable and notorious facts.  For the restoration of letters in the fifteenth century had not at first mended matters, so strong was the dread of Nature in the minds of the masses.  The minds of men had sported forth, not toward any sound investigation of facts, but toward an eclectic resuscitation of Neoplatonism; which endured, not without a certain beauty and use—­as let Spenser’s ‘Faery Queen’ bear witness—­till the latter half of the seventeenth century.

After that time a rapid change began.  It is marked by—­it has been notably assisted by—­the foundation of our own Royal Society.  Its causes I will not enter into; they are so inextricably mixed, I hold, with theological questions, that they cannot be discussed here.  I will only point out to you these facts:  that, from the latter part of the seventeenth century, the noblest heads and the noblest hearts of Europe concentrated themselves more and more on the brave and patient investigation of physical facts, as the source of priceless future blessings to mankind; that the eighteenth century, which it has been the fashion of late to depreciate, did more for the welfare of mankind, in every conceivable direction, than the whole fifteen centuries before it; that it did this good work by boldly observing and analysing facts; that this boldness toward facts increased in proportion as Europe became indoctrinated with the Jewish literature; and that, notably, such men as Kepler, Newton, Berkeley, Spinoza, Leibnitz, Descartes, in whatsoever else they differed, agreed in this, that their attitude towards Nature was derived from the teaching of the Jewish sages.  I believe that we are not yet fully aware how much we owe to the Jewish mind, in the gradual emancipation of the human intellect.  The connection may not, of course, be one of cause and effect; it may be a mere coincidence.  I believe it to be a cause; one of course of very many causes:  but still an integral cause.  At least the coincidence is too remarkable a fact not to be worthy of investigation.