I'm reading Clive James’ Cultural Amnesia, which is a series of essays that uses cultural figures of the 20th century as jumping-off points. I've never heard of most of the people, but the book is very interesting. In James' piece on French sociologist Raymond Aron, a liberal who despised the French left's embrace of the Soviet Union, there was this line (p. 38):
After the Liberation, (Aron) could be heard ... reminding himself and his readership that, despite the immense prestige won by the Red Army for Stalin's regime and the people of the Soviet Union, a system of belief that confused the desirable and the inevitable was still a dogma.
Dogma has a neutral meaning that can take on a negative tone (as in the above quote) when applied outside of religious belief, as the OED lays out in its first definition (italics added by me):
That which is held as an opinion; a belief, principle, tenet; especially a tenet or doctrine authoritatively laid down by a particular church, sect, or school of thought; sometimes, depreciatingly, an imperious or arrogant declaration of opinion.
Dogma is fine in a religion, where the whole points is to take things on faith. In secular life though, dogma is dangerous, and it's the reason why debates on important issues degenerate into idiocy (see the current one on health-care reform).
The American Heritage Dictionary gives this etymology: "Latin, from Greek, meaning opinion, belief, from dokein, to seem, think."