Leviathan and the Air-Pump: Hobbes, Boyle, and the Experimental Life (published 1985) is a book by Steven Shapin and Simon Schaffer. It examines the debate between Robert Boyle and Thomas Hobbes over Boyle's air-pump experiments in the 1660s. In 2005, Shapin and Schaffer were awarded the Erasmus Prize for this work.
On a theoretical level, the book explores the acceptable methods of knowledge production, and social factors related to the different knowledge systems promoted by Boyle and Hobbes. The "Leviathan" in the title is Hobbes's book on the structure of society, Leviathan, or The Matter, Forme and Power of a Common Wealth Ecclesiasticall and Civil and the "Air-Pump" is Robert Boyle's mechanical instrument. The book also contains a translation by Schaffer of Hobbes's Dialogus physicus de natura aeris. It attacked Boyle and others who founded the society for experimental research, soon known as the Royal Society.
Intention of the work Shapin and Schaffer state in their first chapter, "Understanding Experiment", that they wish to answer the question, "Why does one do experiments in order to arrive at scientific truth?"Shapin & Schaffer 1985, p. 3 Their aim is to use a historical account of the debate over the validity of Boyle's air pump experiments, and by extension his experimental method, to discover the origins of the credibility that we give experimentally produced facts today. The authors wish to avoid "'The self-evident'"Shapin & Schaffer 1985, p. 4 method, which (they explain) is when historians project the values of their current culture onto the time period that they are studying (in this case valuing the benefits of empiricism). They wish to take a "stranger's" viewpoint when examining the debate between Hobbes and Boyle because, in the 1660s, both methods of knowledge production were well respected in the academic communityShapin & Schaffer 1985, p. 8 and the reasons that Boyle's experimentalism prevailed over Hobbes's natural philosophy would not have been obvious to contemporaries.
They explain that, traditionally, Hobbes's position on natural philosophy has been dismissed by historians because historians perceived Hobbes as "misunderstanding"Shapin & Schaffer 1985, p. 12 Boyle's work. Thus, in Leviathan and the Air-Pump, Shapin and Schaffer aim to avoid bias and consider both sides' arguments with equal weight. In addition, they comment on the social instability of Restoration society post-1660. They aim to show that the debate between these two contemporaries had political implications beyond the intellectual sphere, and that accepting Hobbes' or Boyle's method of knowledge production was also to accept a social philosophy.Shapin & Schaffer 1985, p. 14
Chapter II: Seeing and Believing: The Experimental Production of Pneumatic Facts Chapter Two outlines Boyle's theory of knowledge production, which revolves around the creation of the "matter of fact".Shapin & Schaffer 1985, p. 22 This refers to an experimentally generated piece of knowledge separate from a universal theory and that was based on probability. 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.Shapin & Schaffer 1985, p. 23 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".Shapin & Schaffer 1985, p. 24 Thus, because "matters of fact" did not have to be absolute, universal assent was not necessary for the production of knowledge. Boyle made use of three knowledge-producing technologies in order to produce knowledge: "a material technology embedded in the construction and operation of the air-pump; a literary technology by means of which the phenomena produced by the pump were made known to those who were not direct witnesses; and a social technology that incorporated the conventions that experimental philosophers should use in dealing with each other and considering knowledge-claims".Shapin & Schaffer 1985, p. 25
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). However, the integrity of the pump was far from perfect and this leaking is central to the arguments both for and against experimentalism. Shapin and Schaffer assert that three important points should be taken into account when considering the pump itself: "(1) that both the engine's integrity and its limited leakage were important resources for Boyle in validating his pneumatic finding and their proper interpretation; (2) that the physical integrity of the machine was vital to the perceived integrity of the knowledge the machine helped to produce; and (3) that the lack of its physical integrity was a strategy used by critics, particularly Hobbes, to deconstruct Boyle's claims and to substitute alternative accounts".Shapin & Schaffer 1985, p. 30
The arguments about experimentally generated knowledge revolve around two of Boyle's experiments. The first experiment is the Torricellian apparatus placed within the exhausted receiver (the bulb). The result is that the liquid in the inverted tube of the Torricellian apparatus falls, but not to the level of the liquid in the dish at the base of the inverted tube. For Boyle, the water level fell because the air was being evacuated from the bulb and thus its spring and weight were no longer acting on the liquid around the base of the tube holding the liquid in the inverted tube up. 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.Shapin & Schaffer 1985, p. 44 However Boyle was careful not to commit to saying that a vacuum existed in the bulb; he stated only that when air was sucked out of the bulb the level of the liquid in the inverted tube fellShapin & Schaffer 1985, pp. 45 - this was the nature of a matter of fact. The second experiment was based on the theory of cohesion - that "two smooth bodies, such as marble or glass discs, can be made spontaneously to cohere when pressed against each other".Shapin & Schaffer 1985, pp. 47 Boyle's idea was that if two cohered discs were placed in the receiver of the air-pump they would spontaneously separate without the air's pressure to keep them together. However, when the receiver was evacuated, they did not separate - a result which Boyle blamed on leakage and the fact that he could not get enough air out of the receiver to reduce the air's pressure to an appropriate level. It should be noted here that Boyle's definitions of "pressure" and "spring" were never clearly defined,Shapin & Schaffer 1985, pp. 54 which we shall see is one of Hobbes's major complaints.
The air-pump granted access to a whole new branch of "elaborate" experiments. In order to witness the phenomena produced by the pump, one had to have access to a pump - which was vastly expensive and difficult to build. However, the space in which the existing pumps did work was arguably a public space - albeit a restricted one. "The laboratory was, therefore, a disciplined space, where experimental, discursive, and social practices were collectively controlled by competent members".Shapin & Schaffer 1985, pp. 39 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. This social space for discourse had two important restrictions: "dispute over matters of fact" was not allowed, and "the rules of the game by which maters of fact were experimentally produced" was not to be disputed.Shapin & Schaffer 1985, pp. 60 "In Boyle's view the capacity of experiments to yield matters of fact depended not only upon their actual performance but essentially upon the assurance of the relevant community that they had been so performed".Shapin & Schaffer 1985, pp. 55 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". As such, the literary technology was used to create "virtual witnessing" - a technique in which description of the experimental scene is written so that the reader can envision the experiment. "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.'"Shapin & Schaffer 1985, pp. 63 Everything about how Boyle instructed other experimentalists to write stressed honesty. 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."Shapin & Schaffer 1985, pp. 67
In summation, Boyle's theory of knowledge production revolves around assent. All three technologies work towards allowing as many people as possible to come to an agreement about a "matter of fact."
Chapter III: Seeing Double: Hobbes's Politics of Plenism before 1660 The third chapter centers on Hobbes' side of the debate for the effective production of knowledge. However, unlike Boyle, Hobbes denies that natural philosophy can be separated from politics and religion. In the previous chapter, Boyle's "matter of fact" worked towards separation from church and state by remaining objective and probabilistic. For Hobbes, however, "the boundaries Boyle proposed to erect and maintain were guarantees of continued disorder, not remedies to philosophical dissension".Shapin & Schaffer 1985, pp. 81 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." Hobbes was motivated by three things in his attack on Boyle: (1) to save his own reputation as a natural philosopher, (2) to develop a system of knowledge production that secured order and maintained proper goals for natural philosophy (namely precision instead of probability) and (3) to be sensitive to the needs of Restoration society (discussed in more detail in chapter 7).Shapin & Schaffer 1985, pp. 83
Hobbes' denial of a vacuum stems in part from a need for political stability. It follows logically that if there can be a space which is devoid of matter, then that is proof of "incorporeal substance" - an idea that was adopted by priests to gain the allegiance of the people by promising the safety of this substance, the immortal soul. 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.Shapin & Schaffer 1985, pp. 94 He considered incorporeal substance a priestly conspiracy to "usurp power" from the true and legitimate leader - the King.Shapin & Schaffer 1985, pp. 96 The conflict could be resolved "by collapsing the hierarchy [spiritual government and material government] in favour of matter".Shapin & Schaffer 1985, pp. 98 "It was to that end that Leviathan proffered a materialist and monist natural philosophy.".