The so-called argument from evil has as its conclusion "God does not exist." The argument expresses something called the Problem of Evil. This entry will outline the argument and some responses to it.
Much ink has been spilled over the questions regarding rationality of theism (see Faith and rationality)--about whether arguments are needed in order to be rational in believing in God, for example. But we could just as well question The rationality of atheism.
In response to these questions, some atheistic philosophers insist that one can prove that the Judeo-Christian-Muslim God does not exist. One can prove a negative, they say, i.e., one can prove that something does not exist. One show that the very concept of a thing is contrary to known facts. That is how the argument from evil proceeds: if God did exist, then he would eliminate evil from the world; but we see evil all around us; therefore, God does not exist.
Here is the argument, in a more detailed form:
- If God exists, then God is omniscient, omnipotent, and all-loving.
- If evil exists in the world, then either (1) God does not know about it, (2) God cannot eliminate it, or (3) God does not want to eliminate it.
- If God does not know about evil, then God is not omniscient.
- If God cannot eliminate evil, then God is not omnipotent.
- If God does not want to eliminate evil, then God is not all-loving.
- Hence (by premises 2-5), if evil exists in the world, then either God is not omniscient, or God is not omnipotent, or God is not all-loving.
- But evil does exist in the world.
- Thus (by premise 6 and 7) either God is not omniscient, or not omnipotent, or not all-loving.
- Therefore (by premises 1 and 8), God does not exist. (That is, the God of Judeo-Christian-Muslim religions, which is omniscient, omnipotent, and all-loving, does not exist.)
One might find The Problem of Evil in the fact that the premises of this argument seem compelling, but the conclusion is (to theists) unacceptable. Consider now the premises in turn.
Premise (1) simply states some basic facts about the conception of God under consideration: "If God exists, then God is omniscient, omnipotent, and all-loving." Ordinary Christians, for example, certainly do not want to reject premise (1). Other people might end up rejecting this premise, because they want to believe in a different sort of God. Process theologians, for example, reject the notion that God is omnipotent, and the Jewish rabbi Harold Kushner has also questioned the doctrine of omnipotence in some of his books, such as When Bad Things Happen to Good People.
Consider premise (2): "If evil exists in the world, then either (1) God does not know about it, (2) God cannot eliminate it, or (3) God does not want to eliminate it." Why think this? Simply put, for a traditional theist, evil has to have some explanation. Why would a good God allow evil to exist in the world? Maybe he does not know about it; or maybe he can't get rid of it; or maybe he does not want to eliminate it. But is there any other explanation? Perhaps; perhaps not. Suppose God knew about evil, he could eliminate all of it, and he wanted to eliminate all of it; could evil even possibly exist then? Surely not. If God knew about all the evil, and he could get rid of it, and he desired to get rid of it, then God would get rid of it. But then we simply say: suppose that evil does exist. In that case, either God does not know about it, he cannot get rid of it, or he does not want to get rid of it. One of those options is open to us (or perhaps a combination of them). That is what premise (2) says.
Now examine premise (3). "If God does not know about evil, then God is not omniscient." That seems perfectly true. If there is anything that God does not know, then God is not omniscient; what it means to be omniscient is to know everything that there is to know.
Similar things can be said about premise (4). "If God cannot eliminate evil, then God is not omnipotent." That also seems incontrovertibly true. If there is anything that God cannot do--anything that does not involve a contradiction, anyway--then God is not omnipotent. It is sometimes held that to eliminate evil would result in a contradiction; that is, we live in the Best of All Possible Worlds (a view made famous by Gottfried Leibniz). But let us set this view aside for the time being. If God were omnipotent then, it seems, he could eliminate evil.
So both premises (3) and (4) seem unobjectionable.
Next consider premise (5), which is perhaps more interesting. "If God does not want to eliminate evil, then God is not all-loving." This premise seems more doubtful. In fact I am sure that a lot of you will want to raise objections to it. Is it not at least possible that God is all-loving, but he still does not want to eliminate the pain and suffering in the world? Maybe it is perfectly consistent for an all-loving God to allow evil to exist in the world. We will elaborate this point in a bit. Just keep in mind that we are going to come back to it; so premise (5) is the first premise we have found that is possibly dubious.
Premise (6) follows deductively from premises (2)-(5); the only way to reject premise (6) is to reject (2), (3), (4), or (5).
Premise (7) is: "But evil does exist in the world." Some people deny this. Some people say that evil is merely an appearance; it is only an illusion. Nothing is really evil. In a certain frame of mind, evil might seem powerless and inconsequential. What really matters is goodness, happiness, love, or something like that; so evil does not matter, and in a sense it does not really exist.
It is difficult for most people to take this view seriously. First of all, even if evil "doesn not really matter," it nevertheless plainly exists. Hitler exterminated six million Jews; that was surely evil. People suffer from debilitating diseases all around the world; that too is surely an evil (a so-called "natural evil"; see below) we all potentially face. People are regularly killed by tornados, earthquakes, hurricanes, and other natural disasters. Those events are awful evils. It sounds extremely implausible, to most people, to say that their obvious hatefulness or badness is illusory. Unless one has some sophisticated way to explain why evil is merely illusory, this view can be safely rejected.
Premise (8) reads: "Thus (by premises 6 and 7) either God is not omniscient, or not omnipotent, or not all-loving." This is a further inference from earlier premises, so the only way that we can reject it is by rejecting those earlier premises.
After going over each premise of the argument from evil, we have found one premise, namely (5), and perhaps also premise (4), that gives us substantial hope of escaping the conclusion. Again: maybe it is perfectly consistent for an all-loving God to allow evil to exist in the world.
But how? How could a God that is all-loving allow evil not only to exist, but to flourish in the world? That is the project of giving a theodicy (q.v.).
Some theologians--of a mystical bent--believe that all they have to prove is that a loving God can have some purpose in permitting evil to exist. These people deny that they have to state God's purposes. There would be little point in doing that. God's purposes are not our purposes, they say; the nature of God is mysterious. All one has to do is to argue that a loving God might have some reason for allowing the existence of evil; one need not state what the reason is. This is an extremely popular view among ordinary theistic nontheologians, for two reasons, no doubt: first, it seems extremely pious not to try to guess at God's thoughts (indeed, some religions enjoin us from doing so); and second, it gives us a reason for not making an actual attempt to explain evil, which promises to be a difficult task.
Let us review a few actual attempts to explain evil (without necessarily endorsing any of them).
We might explain evil by pointing to the existence of free will. God gave us free will; so we are able to bring evil upon ourselves. We are to blame for the evils which we inflict and suffer. This is an unfortunate consequence of our status as free beings. But it is far better that we are free, and hence that we suffer evil, than it would be if we were merely unfree pawns in a perfect game that God played by himself.
This is very persuasive to many people. But there is a very serious problem with it: very much of the evil--the misfortune--that we suffer is not due, in any direct way, to any choices that human beings make. When the Black Death rode in the late Middle Ages, and wiped out millions upon millions of Europeans, that certainly was not due to any act of any human being. Or take any natural disaster at all: human beings do not cause, and cannot prevent, devastating earthquakes. So we should distinguish between moral evil and natural evil, a distinction we have been blurring up until now. Moral evil is any bad thing that for which humans are responsible; natural evil is any bad thing, such as an earthquake or flood, for which humans are not responsible. Human beings are to blame for moral evil, but they are not to blame for natural evil.
"Ah," one may say, "but we are. Adam and Eve freely committed the Original Sin, of eating of the Tree of the Knowledge of Good and Evil, and we have been paying for that great sin ever since." We could get into specific issues of Biblical exegesis and Church doctrine at this point. Suffice it for now to say that it would seem to be rather harsh, to say the least, that absolutely every member of the human race who came after Adam and Eve should have to pay, throughout their lives, with all manner of suffering, for that Original Sin of Adam and Eve. This, according to many, is something that a loving God would do.
Here is another answer. A universe in which we are tested and improved by having to face evils is far better than a universe in which we might complacently live in blissful ignorance of evil. The souls who will inhabit heaven will be far better and stronger if they live in a world beset with all sorts of evils. Evil improves us. So God has allowed Satan to come to the power that he now has. Satan tempts us and if we resist, we are better for it. Satan also tests our will and resolve with all sorts of natural evils, earthquakes, floods, and whatnot; if we pass the test we are better for it.
If one wanted to, one could bring a lot of objections to this. Surely the absolute horrors that humanity has faced, especially in the twentieth century, are unnecessary to improve our moral mettle. We could insist on such objections at length. But then we are engaging the project of theodicy in detail, a topic for Theology more than for Philosophy of religion.