 Tsongkhapa's life falls roughly into an earlier and later period. The later period is defined by a series of publications, beginning in about 1400, which systematically present his mature philosophy. Tsongkhapa, influenced by the divisions used by the editors of the Kanjur, treats non-tantric and tantric sources separately. His philosophical views on tantra, and, to a certain extent his work on ethics fall naturally into separate categories. The later period of his life includes a period of institution building, possibly with an eye to the founding of a new school or sect.