FOR a party that boasts of a rationalist ideology, it must have come as a shock. In the last week of March, Andhiyur Selvaraj, a DMK minister, took part in a temple fire-walking ceremony, ostensibly to ensure the survival of the ruling government. Chief Minister M. Karunanidhi was so peeved with this obscurantist act that he demanded a public apology. The fire-walking ceremony is part of the "Amman cult" of Tamil Nadu, where devotees walk barefoot on fire to ward off the evil eye.