Let me be abundantly clear: Behaving morally is not the same thing as having a coherent moral system.
Oh, I get it! Fear of punishment.
I contend that those religionists who blindly hold up–against others–or personally uphold the ridiculous notion of Absolute Moral Truths, as laid out in supposedly 'revealed'* religions, lack a coherent moral system because much that they propose actually contradicts other moral edicts.
Historically, the faithful have taken the attitude that a variety of manoevres can get them off the Sin-Damnation hook:
† special dispensations for wrongdoing provided by the Pope–go ahead Henry, off with her head, just don't divorce her!
† deathbed confessions of sins to a priest
† confess to the priest and say the required number of Hail Marys so that you can clear your conscience to repeat activities that should not have been banned in the first place
† pay your indulgence, pass through purgatory promptly
† a personal fave–join the Mormon church, tithe your income, submit the names of dead relatives to gain them retrospective admission to a Higher Celestial Plane (or some such advertized perquisite of membership)
You get the idea.
More recently, we have the crop of pro-lifers who murdered abortion doctors; adult human life, after all, being clearly of less value to God than embryonic tissue.
We also have all those religious zealots who believe that they will be rewarded with a Ticket to Paradise if they murder other of their god's children who practice a different religion.
Quite recently a woman was sentenced to death by stoning in a Muslim African nation. The sentence was to be carried out as soon as the woman had delivered the child born of an adulterous incident. The man's sentence?–no trial and no punishment.
The list could go on.
Now, regarding the assertion that atheists can't have a real and consistent reason for behaving rationally: I agree that atheists need to spend more time considering the question, because atheistic systems of morality seem to be a pretty slippery subject.
Atheistic systems are typically less slippery and better thought out than rigid theistic moralizations**, so I think that this blogger needs to look around carefully. Most atheists whom I know primarily apply the do-no-harm criterion to moral thinking and rank much higher on the Kohlberg scale than unthinking punishment-reward-focussed theistic moralizers.
I do believe its possible for atheists to have self-consistent belief systems, its just not possible for them to justify preferring one system over another.
This blogger really does need to educate himself, since it is relatively simple for any thinker to justify a coherent system of morality–and to follow it–and to be an atheist at the same time.
* This refers the fatally circular claim that the Bible is true because it is the (revealed) Word of God.
** Moralizations refers to moralistic pronouncement that are motivated by punishment-reward attitudes and stem from unthinking acceptance of religious edicts rather than of actual moral principles.
atheismChristianityfallacies of logicIslammoralityphilosophypsychologyreligionsociology