As people learned of Robert Boyle's exciting air-pump experiments, published in 1660 as New Experiments Physico-Mechanical, Touching the Spring of the Air and Its Effects, the question of whether a vacuum could exist in nature was more keenly debated than ever before. Matthew Hale remarked that the subject of the experiments “is seeingly trivial …yet it hath exercised the wits and pens of many learned men.” Some of the “many excellent Philosophers” debating the possible existence of “that brave nothingness” continued to uphold the view that nature was frightened by empty space, that “fearful void,” and would fight to prevent it. This view had long been accepted as a fundamental tenet of Aristotle's, who had predicted that after reading arguments in his Physics the concept of “the so-called void will be found to be really vacuous.”

In the 1660s, however, the view that nature abhors a vacuum was no longer widely held. Of course, the Cartesian version of the mechanical philosophy of nature reflected the Aristotelian notion that there were no empty spaces in nature. The atomic version of mechanism, however, asserted the existence of void between the atoms.