It was the steady rise of this tide of opposition in which Cromwell saw the doom of his cause. That it could permanently be upheld by the sword he knew to be impossible. What he had hoped for was the gradual winning of England to a sense of its worth. But every day the current of opinion ran more strongly against it. The army stood alone in its purpose. Papist and sceptic, mystic and ceremonialist, latitudinarian and Presbyterian, all were hostile. The very pressure of Cromwell's system gave birth to new forms of spiritual and intellectual revolt. Science, rationalism, secularism, sprang for the first time into vivid life in their protest against the forced concentration of human thought on the single topic of religion, the effort to prison religion itself in a system of dogma, and to narrow humanity with all its varied interests within the sphere of the merely spiritual. Nothing is more significant, though to Cromwell nothing would have been more unintelligible, than the simple story which tells us how from the vexed problems, political and religious, of the times, men turned to the peaceful study of the natural world about them. Bacon had already called men with a trumpet-voice to such studies; but in England at least Bacon stood before his age. The beginnings of physical science were more slow and timid there than in any country of Europe. Only two discoveries of any real value came from English research before the Restoration: the first, Gilbert's discovery of terrestrial magnetism in the close of Elizabeth's reign; the next, the great discovery of the circulation of the blood, which was taught by Harvey in the reign of James. Apart from these illustrious names England took little share in the scientific movement of the Continent; and her whole energies seemed to be whirled into the vortex of theology and politics by the Civil War.
But the war had not reached its end when, in 1645, a little group of students were to be seen in London, men "inquisitive," says one of them, "into natural philosophy and other parts of human learning, and particularly of what had been called the New Philosophy . . . which from the times of Galileo at Florence, and Sir Francis Bacon (Lord Verulam) in England, hath been much cultivated in Italy, France, Germany, and other parts abroad, as well as with us in England." The strife of the time indeed aided in directing the minds of men to natural inquiries. "To have been always tossing about some theological question," says the first historian of the Royal Society, Bishop Sprat, "would have been to have made that their private diversion, the excess of which they disliked in the public. To have been eternally musing on civil business and the distresses of the country was too melancholy a reflection. It was nature alone which could pleasantly entertain them in that estate." Foremost in the group stood Doctors Wallis and Wilkins, whose removal to Oxford, which had just been reorganized by the Puritan Visitors, divided the little company in 1648 into two societies, one at the university, the other remaining at the capital. The Oxford society, which was the more important of the two, held its meetings at the lodgings of Dr. Wilkins, who had become Warden of Wadham College; and added to the names of its members that of the eminent mathematician Dr. Ward, and that of the first of English economists, Sir William Petty. "Our business," Wallis tells us, "was (precluding matters of theology and State affairs) to discourse and consider of philosophical enquiries and such as related thereunto, as Physick, Anatomy, Geometry, Astronomy, Navigation, Statics, Magnetics, Chymicks, Mechanicks, and Natural Experiments: with the state of these studies, as then cultivated at home and abroad. We then discoursed of the circulation of the blood, the valves in the _venæ lacteæ_, the lymphatic vessels, the Copernican hypothesis, the nature of comets and new stars, the satellites of Jupiter, the oval shape of Saturn, the spots in the sun and its turning on its own axis, the inequalities and selenography of the moon, the several phases of Venus and Mercury, the improvement of telescopes, the grinding of glasses for that purpose, the weight of air, the possibility or impossibility of vacuities, and Nature's abhorrence thereof, the Torricellian experiment in quicksilver, the descent of heavy bodies and the degree of acceleration therein, and divers other things of like nature."