Buddhism, as it developed in India from the time of its founder until the emergence of Mahayana, contains the earliest forms of this religion. It also encompasses the major issues surrounding it.

When did the historical Buddha live? How was the main source from which we draw information about this period, the Pali Canon, formed? What is its reliability? What teachings does it contain? What difficulties does research encounter in locating and reconstructing it? What do terms like "nirvana," "dependent origination," and "non-self" mean?

The author shows that for all of these questions, there is no clear and certain knowledge, but a continuous effort by specialized scholars to find the correct answers. In this brief yet comprehensive introduction, he attempts to present ancient or Indian Buddhism through an overview of the scientific research surrounding these issues, providing a clear picture of the relevant discussions.