Over a long period of time, I have been observing students involved in demonstrating theorems. [1] The demonstrations were intended to be individual activity, but were carried out within a classroom setting and were therefore able to be considered as social activity. I noticed that, although there were many typologies of more or less spontaneous behaviour presented to satisfy the teacher’s request (i.e., a pattern more or less bound to Aristotelian or Megarian-Stoic logic), some students’demonstrative modality could have been thought about in a different way from the one expected by the teacher. This modality brought clearly to mind quite a different kind of logic, highlighting certain factors such as the use of examples or the preliminary enunciation of the thesis.

The nyaya approach described in this article shows that other cultures have produced intellectual mechanisms of ‘truth’ generalization and predication different from Aristotle’s logic (see, for example, Needham, 1959; D’Amore and Matteuzzi, 1976; and more recently, Sarma, 2005; Sarukkai, 2005). Both the ideas of collecting evidence of the implicit and unaware use of this logic, along with an analytic perspective, gave rise to this article. I initially introduce the basic elements of this logic, followed by the presentation of three illustrative cases. I finally present some concluding remarks and reflections.