Divine command theory essentially states that an action is morally right because a higher power (commonly referred to as "God") has decided that the action in question is morally wrong. The question then becomes:
Quote from socrates
“Does God command this particular action because it is morally right, or is it morally right because God commands it?”
Let's say that morality ultimately stems from God, and the righteous are rewarded in the afterlife. This is a simple case of carrot-and-stick "do as you are told, and you shall be rewarded." However, if a few years of living "morally" leads to a happy afterlife, why should we care about anything else in this life? The only things we should do are those that are affirmed to be good by God, as He decides all in the universe. It is a reason to live a moral life, and with the current moral codes prescribed by the major religions, being moral provides order and stability to the world.
But, if an action is good simply because God says so (divine command theory), then something harmful, like theft, could be declared good by God. Morality is therefore dependent on a (supposedly) omnipotent being--or more accurately, someone's interpretation of divine will. With thousands, if not, millions, of religions and sects each claiming to have a more accurate picture of God's will than the others, only faith, unproved by empirical data, can lead to moral truth. Obedience, not reason, is the key to living a righteous life, as humans are not wise enough to comprehend morality. Of course, if one is 100% confident that their moral code is both absolute and supported by the divine, there's no need to question God's will, or consider any errors in understanding the divine will.
One arguing for the divine command theory might say that, "God says theft is wrong, and most people agree that theft is wrong, so there's no point in arguing hypotheticals." That doesn't answer Socrates' question. Let's say that we were certain that we had found the perfect word of God, and it clearly stated a set of moral rules to live by--one of which states "Theft is good." We ask God, "Why is theft moral?" and He does not reply. Are we not wise enough to understand the underlying reasons? It is certainly possible. But if there are underlying reasons, divine command theory breaks, as the source of righteousness does not stem from God's whim.
In a similar situation, we ask the Creator the same question under the same circumstances, but this time He responds. He explains the reasons and humans understand. Once again, the base of morality rests in reason, not on divine whim. In both of these situations, the action (theft) is intrinsically good, and morality is independent of God. The divine command theory is therefore no better than an appeal to authority.
There is also the theory that a) God is omnibenevolent, b) goodness is independent of God and c) God is required to "pass on" righteous morals because is omnibenevolent. (To command humans to commit immoral actions would be akin to committing immoral actions himself). Even if this is the case, morality would still be independent of God, and therefore God would not be required for morality.
Some who argue against divine command theory believe that there is no absolute morality. Morality can be relative to time and place. A prehistoric hunter killing deer for food may be moral, but killing tigers for sport may not be. Attacking a serial killer that has invaded your house may be moral, but invading someone else's house with intent to commit murder may not be moral.
There is another situation: what if there is no higher power? If God does not exist, divine command theory cannot exist. If there are two options (God exists/God doesn't exist), and we know nothing else, probability states that there is a 50% chance that some higher power exists. That means, in 50% of hypothetical universes (perhaps our own) divine command theory cannot be true. Of course, that also means there is a 50% chance that God does exist, and if He is omniscient, He is watching your every immoral action.
So is divine command theory the basis for an absolute moral code? And if divine command theory is not the basis for morality, what is?
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