Once upon a time, the word 'superstition' meant something, namely, a vice, opposed the virtue of religion (rendering what is owed to God) by excess: what should be rendered to God is rendered to more than God or to God in an undue way. Since the virtue of religion was to render right devotion to God, the first type of superstition was the rendering of devotion to the wrong sort of thing. This was called idolatry. Insofar as the virtue of religion had to do with following the teaching of God, the second sort of superstition was called divination, the following of non-divine teaching as if it were divine. Insofar as the virtue of religion directed human actions according to divine precepts, the third sort of superstition was superstitious observance, as in the use of amulets and the like.
Then the word became opposed to what was called 'rational religion', which was not a virtue in the old sense but a set of principles, and it was applied to anything that deviated from this standard, even if it would not have counted as superstition before. Thus 'superstition' became a less robust word, more vague, and while it continued to carry hints of irrationality and vice, it became more an insult than anything.
Then someone came along with the bright idea of abolishing religion altogether, because it was all superstition. And this use of the word 'superstition' meant almost nothing; it was a word like 'damned' or 'stupid' in ordinary conversation. It lent a flavor of irrationality to anything to which it was applied, but nothing more. They would still say the same things as when 'superstition' had been opposed to 'rational religion', but now instead of meaning anything significant by it, they just meant, 'It's stupid,' often saying it in a tone of voice indicating peremptory dismissal. And so the word, which had once been applied with such careful distinction and deliberation, became an excuse for not doing any critical thinking at all. In particular, it was a way of dismissing things that seemed less minimalist than one would like. When people would bring up the suggestion that there was more than a particular minimalist view would allow, they were dismissed; and the anathematization applied: "That's just an outdated superstition." And the people who used this cliche in order not to have to reason out any precise objections would go on and be satisfied in an absolute certainty of their eminent rationality.
