Logical machines
Logical machines
Mechanical devices or instruments designed to effect combinations of propositions, or premisses, with which the mechanism is supplied, and derive from them correct logical conclusions. Both premisses and conclusions may be expressed by means of conventional symbols. A contrivance devised by William Stanley Jevons in 1869 was a species of logical abacus. Another constructed by John Venn in 1881 consisted of diagrams which could be manipulated in such a manner that appropriate consequences appeared. A still more satisfactory machine was designed by Allan Marquand in 1882. Such devices would indicate that the inferential process is mechanical to a notable extent. — J.J.R-