Logic Machine of Benjamin Burack
date: label: date made
content: ca 1936
name: label: maker
content: Burack, Benjamin
notes: label: Description
content: The Logic Machine that is mounted inside the top of a suitcase (image 78-16600) was designed by Benjamin Burack in 1935 when he was a junior at Lewis Institute, a college that later merged Armour Institute to become Illinois Institute of Technology. Burack designed the machine after taking a logic course in which his professor “claimed that, since formal logic was `mechanical’ . . . it should be possible to build a machine which could detect whether a syllogism was logical or illogical.” (Benjamin Burack to John Pfeiffer of <I>Scientific American</I> September 14, 1949) After Burack told his professor that he had designed such a machine, Lewis Institute financed the approximately six-month project to build it. This included hiring an engineering student to construct a board containing electronic contacts on which three wooden blocks with holes, some of which contain metal contacts, can be mounted. The original name of the machine was the Formal Fallacy Detector (see 1986.0870.03).
label: Description
content: A syllogism is comprised of three propositions, each of which has one of four forms: A (X is Y), E (no X is Y), I (some X is Y), or O (some X is not Y). Among the blocks seen in the bottom of the suitcase (see image 78-16602) six different sets of propositions of the form A, E, I, and O where X and Y are represented by two different letters from among M, P, and S are seen marked on the edge of 24 blocks. The actual propositions appear on the front of the blocks, three of which are seen mounted on the contact areas in the top of the suitcase (see image 78-16601).
label: Description
content: If the form of the syllogism is not one that produces a valid logical conclusion one or more light bulbs mounted inside the top of the suitcase flash next to the reason or reasons why the argument is not valid (see image 78-1660). The machine only tested the validity of the argument not whether or not it gave a true conclusion, for example, if one of the assumptions is false, the conclusion could also be false.
label: Description
content: While there are many documents in the collection describing the workings of the Logic Machine (see numbers 1986.0870.02 - 1986.0870.10), it is not clear that they all correlate with the physical machine as it was constructed.
label: Description
content: Reference:
label: Description
content: Burack, Benjamin. “An Electric Logic Machine” <I>Science</I>, June 17, 1949, vol. 109, issue 2841, pp. 610-11.
label: Location
content: Currently not on view
place: label: place made
content: United States: Illinois, Chicago
topic: label: Subject
content: Psychology
label: Subject
content: Mathematics
setName: label: See more items in
content: Medicine and Science: Mathematics
creditLine: label: Credit Line
content: Gift of Benjamin Burack
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1986.0870.01
label: catalog number
content: 1986.0870.01
label: accession number
content: 1986.0870
objectType: label: Object Name
content: Logic Machine
physicalDescription: label: Measurements
content: overall, closed: 16.7 cm x 45.5 cm x 46 cm; 6 9/16 in x 17 29/32 in x 18 1/8 in