The Cambridge History of India, Vol. I: Ancient India v1.c28.32

v1.c28.32

The population, as we learn from Megasthenes² in agreement with the indications of the Arthaçāstra, consisted of seven classes, which have been already particularised³: there was no transference from one class to another (except that the philosophers, i.e. the Brāhmans, might in case of adversity adopt any profession), nor was marriage between them allowed⁴. These distinctions of function correspond only partially to those of caste, which in fact must have been already much more complicated: and they take no note of special cases, such as riverine and maritime populations.