# Mathematical Treasure: Jevon's Pure Logic & Logic Piano

Author(s):
Frank J. Swetz (The Pennsylvania State University)

William Stanley Jevons (1835-1882) was a British economist and logician. In his Pure Logic or the Logic of Quality Apart from Quantity (1864), he challenged the approach taken by George Boole in his work on logic. Jevons also showed an interest in the non-Euclidean geometries of his time, again questioning the logic of their formation. Among his other achievements was the construction of a “Logic Piano,” a mechanical computer to undertake logical demonstrations.

In Chapter XV (below), Jevons stated his objections to Boole's logic.

Jevon's first objection.

Jevon's second objection.

Jevon’s Logic Piano was the first modern machine to undertake logical inference.

This material is obtained through the courtesy of the Peabody Library of Johns Hopkins University.

Index of Mathematical Treasures

Index of Mathematical Objects

Frank J. Swetz (The Pennsylvania State University), "Mathematical Treasure: Jevon's Pure Logic & Logic Piano," Convergence (April 2017)