This facility has been created for the use of anyone interested in or researching Charles Dodgson’s 'Game of Logic'.

The 'game of logic' is a diagrammatic means of representing two propositions from which a logical conclusion can be drawn and was developed between 1884 and 1886 as a tool for teaching elementary logic to children. The 'game' is designed to enable an understanding of the syllogism - a form of logical problem originally defined by Aristotle which gained considerable interest among logicians and mathematicians in the mid-19th century.

Dodgson initially set out to explore better ways of solving syllogisms which set him on a path to write a three-volume text on symbolic logic, of which only the first volume (Symbolic Logic - Part 1) was published. Whilst writing the first volume of Symbolic Logic and developing the ideas which were intended for the second and third parts, Dodgson digressed to publish The Game of Logic, a short book intended just to introduce the idea of the syllogism and show how such problems could be solved using his diagrammatic method. Dodgson tested out the method in several schools and believed it to be an entertaining way to introduce the subject, which he thought was an essential part of everyone's education.

The 'Premises' section on this site describes the basic forms of logical problems which the 'Game' can be used to solve.

The 'Diagrams' section shows how premises† are plotted on Dodgson’s diagrams and how a conclusion is drawn from them.

The 'Demonstrator' is an interactive page allowing the user to work though example problems.

The section labelled "Sq of Opposition" is an interactive facility for exploring how different forms of proposition relate to each other, and showing distinctions between how Dodgson interpreted the meanings of propositions and how they were traditionally regarded.



†Although Dodgson used the spelling "premisses" in his publications, for this website, we use the more common spelling "premises".