“In Jainism we find only one system of metaphysics, but in Buddhism many. And when Buddhism disappeared, it was not due to any violent religious conflicts within the Indian religious tradition, but in part to the invasion of Islam, and in part to the gradual development of its own doctrines towards the Upaniṣadic ones, and to the ease with which the developed doctrines could be assimilated and adopted by the philosophies based upon the Upaniṣads. Buddhism never attempted to formulate its own codes of social conduct, allowed the castes to continue as such, and, confining itself to the monasteries, sought only to teach spiritual doctrines and discipline. To be sure, it did not allow caste distinctions within monasteries, and like Jainism, established nunneries for women ascetics.”