Release date is 2026-05-13

Seven philosophical problems -- Decameron physiologicum -- Proportion of a straight line to half the arc of a quadrant -- Six lessons to the Savilian professors of mathematics -- Στιγμαι [Stigmai], or marks of the absurd geometry, etc., of Dr. Wallis -- Extract of a letter from Henry Stubbe -- Three papers presented to the Royal Society against Dr. Wallis -- Considerations on the answer of Dr. Wallis -- Letters and other pieces.

Emmanuel Ackerman, KD Weeks and the Online Distributed Proofreading Team at https://www.pgdp.net (This book was produced from images made available by the HathiTrust Digital Library.)

"The English works of Thomas Hobbes of Malmesbury, Volume 07 (of 11)" by Hobbes is a collection of natural philosophy and mathematical treatises written in the mid-17th century. The volume ranges across mechanics, optics, geometry, tides, and weather, and includes Hobbes’s polemics against contemporary mathematicians. It showcases his materialist method: mechanical explanations for natural effects, bold geometric constructions (notably a proposed duplication of the cube), and a sustained critique of the misuse of algebra in geometry.

The opening of the volume begins with a royal dedication and a short apology for Leviathan, after which the “Seven Philosophical Problems” unfold as a dialogue between A and B. B advances a unified mechanical physics: gravity and tides arise from large-scale motions that “cast off” air; there is no vacuum, and air‑pump marvels are reinterpreted as strong inflows of air; heat is exhalation from motion, and light a pressure effect on the senses; hardness comes from swift internal reciprocations, explaining elasticity, brittleness, Prince Rupert’s drops, freezing, and the formation of ice. He sketches a meteorology of evaporation, cloud gathering, rain and snow, hail and thunder, accounts for winds and why ships can sail near the wind, and distinguishes reflection, refraction, impact, recoil, and magnetism by shared motions rather than occult qualities. The section culminates in a geometric construction for duplicating the cube and an attack on algebraic “confutations,” arguing they illegitimately mix units (lines, areas, volumes) and thus produce numerical equalities that are false in geometry. (This is an automatically generated summary.)

Originally published: London: John Bohn, 1839