This paper breaks down secularism into analytically tractable strands. We distinguish among innate, instrumental, and principled secularisms and also between passive and active secularisms. We show that the acceptability of secularism within a society is contingent on the level of aggregation, the reference group and the dimensions of religion under consideration, the cost of contest, and the relative strength of non-secular actors. We then relate the establishment policy of the state to the acceptability of secularism among the various sub-sets of the society and show that the ruler does not establish his own religion either when he is absolutely tolerant or when the administration is very inefficient.