This is in direct opposition to Hobbes (discussed in chapter 3), who required "absolute certainty" based on "logic and geometry" to consider a phenomenon a fact.

[7] In the eyes of Boyle and his colleagues, the abandonment of absolute certainty was not "a regrettable retreat from more ambitious goals; it was celebrated as a wise rejection of a failed project".

[9] Importantly, Shapin and Schaffer give a description of the "material technology," the air-pump itself, essentially a suction pump attached to a replaceable glass bulb.

When the pump was set in motion, the air would be evacuated from the glass bulb thus creating what we now consider to be a vacuum, but what for contemporaries was a space of great debate (explained below).

The fact that the water did not fall completely to the bottom of the tube was explained (for Boyle) by the existence of air in the bulb that occurred due to leakage.

[15] The collective viewing of the air-pump experiments avoided the problem of single eye-witness testimony (which was unreliable), and it offered a space for discourse.

[17] In order to expand his audience (and credibility) Boyle recommended to the academic community that replication was crucial, though he admitted that others "[would] find it no easy task".

"Stipulations about how to write proper scientific prose were dispersed throughout [Boyle's] experimental reports of the 1660s, but he also composed a special tract on the subject of 'experimental essays.

He wanted readers to read circumstantial accounts of failed experiments as well as successes, and he asserted that all physical causes should be stated as only "probable.

[20] Hobbes also argued for "proper metaphysical language", in contrast to Boyle's reluctance to address the issue of a vacuum and his vague concept of air "pressure."

This splits the allegiance of each person in a country between the Church and the Monarch, which creates social instability and ultimately, for Hobbes, the risk of civil war.

Hobbes also rejects the idea that the senses were reliable enough to be able to provide factual knowledge[26] because "the same impressions could be obtained dreaming or waking, by the motions of matter in real external object or by rubbing the eyes".

[26] Instead, Hobbes posits that man's own agency is the place for natural philosophy, once again drawing on geometry: "'as we know, that, if the figure shown be a circle, then any straight line through the centre shall divide it into two equal parts.'

- He systematically refused to credit experimentalists' claims that one could establish a procedural boundary between observing the positive regularities produced by experiment (facts) and identifying the physical cause that accounts for them (theories).

- He contended that, whatever hypothetical cause or state of nature Boyle adduced to explain his experimentally produced phenomena, an alternative and superior explanation could be proffered and was, in fact, already available.

"[43] In his Defense, Boyle restated that "he could not understand why Linus, like Hobbes, had attacked him as a vacuist when he had explicitly declared his nescience on the matter and had identified the question as metaphysical in character" and thus out of the range of experimental exploration.

Thus, in response, Boyle "defended the autonomy and status of his [experimental] community" as separate from other social bodies (such as the Church)[50] and wrote "of 'the doctor's grand and laudable design, wherein [he] heartily wish[ed] him much success of proving the existence of an incorporeal substance.

"[51] Thus, from this chapter we see that above all Boyle wished to defend his experimental method, its separation from other bodies of knowledge, and lastly his personal claims about the spring of the air.

"[55] However, "for more than eighteen months neither of Huygens' claims were granted the status of matters of fact" and it is in this time period that we see how the troubles of replication were dealt with by contemporaries.

"[60] "Hobbes and Boyle used the work of the 1640s and 1650s to give rival accounts of the right way to conduct natural philosophy"[61] and, in chapter 7, Shapin and Schaffer show how those models were interpreted and supported by Restoration society.

'"[62] "These exchanges give considerable point to the proposals that Boyle and his allies produced for the establishment of a social space in which dissent would be safe and tolerable.

"[62] In addition, "Sprat's History of the Royal Society (1667) labeled Hobbesian dogmatism as tyranny, and uncontrolled private judgement as enthusiasm.

"[62] "The works of Barlow, Pett, and Dury argued that the balance of disputing sects was better than a state that included a cowed and disaffected party coerced into silence.

"[63] "With Hobbes in view...Glanvill insisted that 'dogmatizing is the great disturber both of our selves, and the world with-out us: for while we wed an opinion, we resolvedly ingage against every one that opposeth it...hence grow Schisms, heresies, and anomalies beyond Arithmetick.

[68] In the final chapter of Leviathan and the Air-Pump, Shapin and Schaffer condense their vastly complicated picture of Restoration society and how it interacted with the development of modern science to three points.

[72] Margaret C. Jacob wrote that, for a time, it was the most influential book in the field of history of science, following the trend to relativism with its equation of "scientific discourses" with "strategies of power".

[73] John L. Heilbron credits Shapin and Schaffer with picking important aspects of the development of experimental culture that are still relevant, citing specifically the problems with replication.

In addition, Heilbron laments the absence of comparisons to the development of empiricism in the rest of Europe because it blinds the reader to what may have been peculiar to England's case.

Both Malcolm and Leijenhorst call attention to the remarkable fact that Hobbes was already attacking incorporeal substances when he was a vacuist, and long before he became a plenist.

[80] Horstmann argues that there are many similar errors and wrong quotations in Leviathan and the Air-Pump and suggests that the chapters dealing with Hobbes are constructed on heavy and sometimes systematic misrepresentations of the historical record.