I'm going to argue for the existence of God from the premise that moral good and evil really exist. They are not simply a matter of personal taste. Not merely substitutes for "I like" and "I don’t like."
Before I begin, let's get one misunderstanding out of the way. My argument does not mean that atheists can't be moral. Of course atheists can behave morally, just as theists can behave immorally.
Let’s start then with a question about good and evil: ‘Where do good and evil come from?"
Atheists typically propose a few possibilities. Among these are evolution, reason, conscience, human nature, and utilitarianism.
I will show you that none of these can be the ultimate source of morality.
Why not from evolution? Because any supposed morality that is evolving can change. If it can change for the good or the bad, there must be a standard above these changes to judge them as good or bad. For most of human history, more powerful societies enslaved weaker societies, and prospered. That’s just the way it was and no one questioned it. Now we condemn slavery. But based on a merely evolutionary model, that is an ever-changing view of morality, who is to say that it won’t be acceptable again one day? Slavery was once accepted, but it was not therefore acceptable. And if you can’t make that distinction between accepted and acceptable, you can’t criticize slavery. And if you can make that distinction you are admitting to objective morality.
What about Reasoning? While reasoning is a powerful tool to help us discover and understand morality, it cannot be the source of morality. For example, criminals use reasoning to plan a murder -- without their reason telling them that murder is wrong. And was it reasoning -- or something higher than reasoning -- that led those Gentiles who risked their lives to save Jews during the Holocaust? The answer is obvious: it was something higher than reasoning -- because risking one’s life to save a stranger was a very unreasonable thing to do.
Nor can conscience alone be the source of morality. Every person has his own conscience and some people apparently have none. Heinrich Himmler, chief of the brutal Nazi SS, successfully appealed to his henchmen’s consciences to help them do the ‘right’ thing in murdering and torturing millions of Jews and others. How can you say your conscience is right and Himmler’s wrong if conscience alone is the source of morality? The answer is you can’t.
Some people say ‘human nature’ is the ultimate source of morality. But human nature can lead us to do all sorts of reprehensible things. In fact, human nature is the reason we need morality. Our human nature leads some of us to do real evil, and leads all of us to be selfish, unkind, petty and egocentric. I doubt you would want to live in a world where human nature was given free reign.
Utilitarianism is the claim that what is morally right is determined by whatever creates ‘the greatest happiness for the greatest number.’ But to return to our slavery example: if ninety percent of the people will get great benefit from enslaving the other ten percent, would that make slavery right? According to utilitarianism it would.
We’ve seen where morality can’t come from. Now let’s see where it does come from.
What are moral laws? Unlike the laws of physics or the laws of mathematics, which tell us what is, the laws of morality tell us what ought to be.
But like physical laws, they direct and order something. And that something is right human behavior.
But since morality doesn’t exist physically -- there are no moral or immoral atoms, or cells or genes -- its cause has to be something that exists apart from the physical world. That thing must therefore be above nature -- or super-natural.
The very existence of morality proves the existence of something beyond nature and beyond man. Just as a design suggests a designer, moral commands suggest a moral commander. Moral Laws must come from a moral lawgiver.
Well, that sounds pretty much like what we know as God.
The consequence of this argument is that whenever you appeal to morality you are appealing to God whether you know it or not; you’re talking about something religious, even if you think you’re an atheist.
I’m Peter Kreeft, professor of Philosophy at Boston College, for Prager University.