§48. Persona Non Grata

In his first work in natural philosophy Hobbes raised no objection against a vacuum, but by the 1640s, he was an ardent plenist (as was Descartes), and insisted, against rising experimental evidence, that a vacuum is an absurd thing impossible in nature.

The anti-scholasticism of the early Royal Society affected more than just the content of their natural philosophy, contributing to an alteration in what could and should be called scientia. Compare the position of Hobbes and Francis Bacon. Hobbes practically never mentions Bacon, whom he some­what knew. He seems to understand that Bacon has nothing to say to him, whereas Boyle views himself as picking up where the impossibly burdened Chancellor left his unfinished work. Hobbes subscribes to the scholastic logic of science, substituting Epicurean-Galilean mechanism for Aristotle’s teleo­logical hylomorphism. For the experimenters of the early Royal Society, the conclusions of natural philosophy never rise above a probability. Hypotheses are provisional and revisable and advanced with arguments that are never full proofs, leaving assent a matter of choice. This condition of natural phi­losophy is not, to them, a regrettable retreat from a lofty ideal. It is a libera­tion from the scholastic straitjacket that has kept natural philosophy infantile since Aristotle.

Hobbes remembers the medical concept of sign and the place Aristotle gave it in practical knowledge, pairing it with prudence rather than scientia:

This taking of signs by experience, is that wherein men do ordinarily think, the difference stands between man and man in wisdom, by which they com­monly understand a man’s whole ability or power cognitive; but this is an error: for the signs are but conjectural; and according as they have seldom or often failed, so their assurance is more or less; but never full and evident: For though a man have always seen the day and night to follow one another hitherto; yet he can not thence conclude that they shall do so, or that they have done so eternally: experience concludeth nothing universally.

In Leviathan he adds, “And therefore he that has most experience in any kind of business, has most signs, whereby to guess at the future time; and con­sequently is the most prudent.” To science, however, this happy empirick remains an outsider. His wisdom is prudence, sound judgment, sagacious conjecture, but not philosophical scientia.¹⁹²

Boyle and Locke reverse this argument. Let us drop the defunct Aristotelian model of scientia, they say, and pursue a new form of natural philosophy on the medical model of qualified experience and a physician’s sagacious conjectures. Hobbes concludes that experiments, revealing no more than signs, cannot belong to scientia. But the ancient doctors pioneered the use of signs as instruments to discover the unseen, methods Boyle and Locke want to draw into natural philosophy, as Democritus and Epicurus did in antiquity. The difference is that the experience newly mobilized is experi­mental experience, something rare in antiquity and unconsidered in ancient natural philosophy.

Hobbes was a Royal Society antitype. He denies the value of experiments in natural philosophy; is dissatisfied with diffidence and demands ultimate causes; and scoffs at the segregation Boyle and his colleagues insinuate be­tween politics and natural philosophy. The authority of the Sovereign reaches every corner. Hobbes denounces the Royal Society's advertised neutrality and publicity. Not only do they claim an independent competence in opinions, as if the Sovereign has no business in their laboratory; that laboratory is not the public space they advertise. Access is restricted; for instance, they will not admit Sir Thomas Hobbes! The whole business is a cunning disguise for a new elite seeking power over citizens. The Society is a public nuisance and its claim to autonomy seditious.