There is a difference between the South and the North on five points. We shall describe the practices of the South: to eat with a person not having received Brahmanical initiation; to eat with one’s wife; to eat food prepared the previous day; to marry the daughter of the maternal uncle or paternal aunt. And for the North: to sell wool; to drink spirits; to traffic in animals with two rows of teeth; to take up the profession of arms; to make sea voyages.
Baudhāyana (c. 800 BCE) on the Brahmins of northern and southern India. Qtd. in A K Ramanujan’s “Is there an Indian way of thinking?”