---
title: "Leviathan and the Air-Pump"
chunk: 5/9
source: "https://en.wikipedia.org/wiki/Leviathan_and_the_Air-Pump"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T04:36:51.494994+00:00"
instance: "kb-cron"
---

== Chapter V: Boyle's Adversaries: Experiment Defended ==
While the previous chapter focuses on the attacks of Boyle's main opponent (Hobbes), this chapter focuses on Boyle's actions in the face of more general adversity.  The three main opponents to Boyle were Hobbes, Linus and More, and Boyle's response to each in turn reflects his opinion of their ideas and shows what parts of his own ideas he deemed essential and what parts he deemed less so.  The figures can be divided into two groups: Linus - who conformed to the model of the experimental programme but did not agree with Boyle's explanation of the air-pump experiments, and Hobbes and More - who attacked the experimental programme as an institution.
"Linus said there was no vacuum in the Torricellian space.  This was apparent because one could see through that space; if there were a vacuum, 'no visible species could proceed either from it, or through it, unto the eye."  Linus offered a nonmechanical solution to the sustained height of the liquid in the Torricellian apparatus.  He suggested that "a certain internal thread (funiculus) whose upper extremity was attached to the finger [blocking the top of the inverted tube] and whose lower extremity was attached to the surface of the mercury."  He also explained that, in the marble disc experiment, the fault was not with the air-pump but rather with Boyle's theory of the spring of the air.  Thus, as far as experimental procedure was concerned, Linus was following the rules. So how would Boyle respond?  While Boyle's response contained a restatement of the rules of experimentation, a restatement of the boundaries of experimental philosophy, a defense of his mechanical interpretation, and a particular defense of the spring of the air, Boyle took great pains to "make clear that he generally approved of Linus's manner of constructing and delivering his criticisms."  Linus was fully welcomed into the experimental community despite his difference of opinion.  Thus, "in his Defense Boyle would therefore demonstrate not merely that Linus was wrong, but also how experimental controversies ought to be conducted."  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.
Hobbes on the other hand attacked the validity of the experimental programme itself.  "Boyle's response to Hobbes was fundamentally a defense of the integrity and value of experimental practices."  Boyle's reply included a technical response detailing the changes he had made to the pump (immersing it in water), a reiteration of the rules of experimental discourse, "an experimental programme devoted to clearing up the troubles which Hobbes had pointed to in his comments on New Experiments," and an ideological rejection of Hobbes's natural philosophy.  In his reiteration of the rules of experimental discourse he defended his empirical method by asserting that the argument was over the interpretation of matters of fact and not the facts themselves, thus keeping the experimental way of life out of the line of fire.  In response to Hobbes's criticism that the air had a subtler part that permeated the pump, Boyle stated that "this aether must either be demonstrated by experiment to exist or it was to be regarded as a metaphysical entity", which Boyle has excluded from the scope of the experimental method.
Henry More had three main arguments in relation to Boyle: "(1) that matter itself was passive, inert and stupid; (2) that its motion was guided by 'some Immaterial Being that exercises its directive Activity on the Matter of the World'; (3) that mechanism alone was an inadequate way of accounting for Boyle's phenomena."  He insisted that natural philosophy could be used "as [a weapon] in theology" which we have seen is an area that Boyle wished to keep separate from the experimental method.  Thus, in response, Boyle "defended the autonomy and status of his [experimental] community" as separate from other social bodies (such as the Church) 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.'"  "Boyle argued that because More's spirit was not a physical principle it could not be part of the language of organized experimenters."
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.