The Elephant's Footprint: An Ancient Indian Logic Diagram
Keywords:logic diagram, set theory, John Venn, Sanskrit, Buddhism, Yoga, South Asia
A seminal article by Margaret Baron, published in 1969, explored the history of set diagrams (Venn diagrams). However, Baron did not look beyond the evidence of European sources. This article presents evidence of a literary simile from ancient India that exemplifies the idea of a larger circle including within it many smaller circles, each circle standing for an ethical concept. The simile – an elephant's footprint enclosing the footprints of smaller animals – first appears in the Buddhist Canon, and it was used occasionally in South Asian literature through the following millennia until the eighteenth century. I argue that the Elephant's Foot simile can be added to Baron’s catalogue of historical cases where ancient authors were using language that implied a simple concept of logical sets.