Comment No surprise it was posted AC then... (Score 3, Insightful) 244
Incidentally, I think you need to read your philosophy coursebook a little more closely. An "atheist" is someone who does not believe in the existence of any gods. That is *it*. Rejection of belief in gods does not, in and of itself, require acceptance of the postulate "you should just be rational."
While it is true that many atheists would probably agree with the statement "you should just be rational," most will have very different ideas about what constitutes "rationality" in any given circumstance and some may object entirely. And in any case, accepting even this statement doesn't reject the possibility of making and honoring laws. Doing so could be considered a very rational behavior (the argument is left to the student).
Being an atheist also does not, in and itself, require rejection of a religion. Many sects of Buddhism, for example, deny the existence of any gods and as such are atheist. New-age weirdos can deny the existence of god as well and still believe in auras and energies and what-not. Again...many atheists might also reject these belief systems, but it is not a requirement of the word.
Some might try to argue that there is a chain of reasoning at work...something like rejection of god means rejection of religion which means rejection of religious codes of morality which means rejections of any code of morality which means acceptance of the only possibility left which is "you should act rationally," but such a chain of reasoning is philosophically sloppy with incorrect assumptions each step of the way. Though being an atheist doesn't automatically make someone a rigorous philosopher, so plenty of atheists might think this way.
I am also curious about how it has been "mathematically proven that there never are any rational course[s] of action." Mathematics generally deals with the modeling of quantifiable relationships, whereas "rationality" is more in the domain of psychology, sociology, economics, and perhaps philosophy. Does the proof look like this?:
Let x =
let y = 1/3
therefore: x = y
therefore 3x = 3y
therefore (3)(.3333...) = (3)(1/3)
therefore (.9999...) = (3/3)
therefore (.9999...) = 1
therefore there is never a rational course of action.
Seems pretty unlikely to me.