# Mathematician:Thomas Hobbes

## Mathematician

English thinker better known for being an astute political philosopher than as a mathematician.

Best known in mathematical circles for believing that he had solved the problem of Squaring the Circle.

Generally considered a mathematical ignoramus, his influence was perhaps of greater importance than generally considered, if only because of the stimulating controversy and discussion he raised.

A member of the informal Académie Parisienne.

## Nationality

English

## History

- Born: 5 April 1588, Westport, Malmesbury, Wiltshire, England
- Died: 4 Dec 1679, Hardwick Hall, Derbyshire, England

## Publications

- 1637:
*The Elements of Law, Natural and Politic*(unpublished at the time) - 1642:
*De Cive*(Concerning Citizenship) - 1646:
*A minute of first draught of the optiques* - 1647:
*De Cive*(second edition) - 1650:
*Humane Nature*(Human nature) and*De Corpore Politico*(Of the body politic) (published without his permission: these were the two parts of his 1637 work*The Elements of Law, Natural and Politic*) - 1651:
*Leviathan* - 1655:
*De Corpore*(On the Body) (containing a large amount of mathematical material, including a few flawed attempts at Squaring the Circle) - 1658:
*De homine*

### Dispute with Wallis

As a result of his publication of efforts at Squaring the Circle, from $1655$ onwards he was involved in an intellectual dispute with John Wallis, whence various publications with titles like:

- 1656:
*Six Lessons to the Professors of Mathematics in the University of Oxford* *The Marks of the Absurd Geometry, Rural Language etc. of Doctor Wallis*

He rejected the new algebraic techniques, claiming that algebraic symbols (because of their potential ambiguity of usage) were unreliable in mathematical proofs.

In particular, he condemned Wallis's work as:

*... a scab of symbols ... as if a hen had been scraping there.*

### Dispute with Royal Society

He also quarreled with the newly-founded Royal Society, in particular with Robert Boyle:

- 1661:
*Dialogus Physicus, sive de Natura Aeris* - 1662:
*Mr. Hobbes Considered in His Loyalty, Religion, Reputation, and Manners*

### ... and so on ...

Had problems with Gabriel's Horn.

In particular he could not make sense of the fact that it has a finite volume but an infinite surface area:

*To understand this for sense, it is not required that a man should be a geometrician or a logician, but that he should be mad.*- -- 1672 (quoted in 1992: George F. Simmons:
*Calculus Gems*: Chapter $\text {A}.15$

- -- 1672 (quoted in 1992: George F. Simmons:

## Critical View

*Hobbes had the curious belief that mathematical theorems can be attacked by ridicule and invective as if they were obnoxious planks in an opponent's political platform.*- -- 1992: George F. Simmons:
*Calculus Gems*: Chapter $\text {A}.15$

- -- 1992: George F. Simmons:

## Sources

- 1986: David Wells:
*Curious and Interesting Numbers*... (previous) ... (next): $3 \cdotp 14159 \, 26535 \, 89793 \, 23846 \, 26433 \, 83279 \, 50288 \, 41972 \ldots$ - 1992: George F. Simmons:
*Calculus Gems*... (previous) ... (next): Chapter $\text {A}.15$: Torricelli ($\text {1608}$ – $\text {1647}$) - 1997: David Wells:
*Curious and Interesting Numbers*(2nd ed.) ... (previous) ... (next): $3 \cdotp 14159 \, 26535 \, 89793 \, 23846 \, 26433 \, 83279 \, 50288 \, 41971 \ldots$