Ockham’s Razor

This is the weekly Q & A blog post by our Research Professor in Philosophy, Dr. William Lane Craig.

Question

Dear Dr. Craig,

First off let me just say what a blessing it is to have such an intelligent, amazing person who defends the Christian faith with truth but also does it with love and compassion! God bless you and your ministry! Now my question today refers to Lee Strobel book "The Case for a Creator". There was one part in the book where Strobel asked you "why does it have to be One Creator?" And you responded by saying "my opinion, Ockham's Razor would shave away any additional Creators." So my question today is in 3 questions:

1. Define what is Ockham's Razor?
2. How does this (scientific) principle or theory eliminate the need for extra gods?
3. How does Ockham's Razor prove the existence of One God?

I absolutely love your ministry and I thank you for taking the time to answer my questions. Know that you are in my prayers and you are one of the many people who inspire me to defend the Christian faith.

Yours in Christ,

Kyle

United States

Dr. William Lane Craig’s Response

Ockham’s Razor (named for the great medieval theologian William Ockham [1287-1347]) is a principle governing inference to the best explanation. It states, Do not multiply causes beyond necessity. In other words, we are justified in positing only such causes as are necessary to explain the phenomenon in question. Positing any further causes would be gratuitous.

Internet atheists sometimes misuse Ockham’s Razor by saying that because atheism is simpler than theism (having one less entity), it is the better view. But Ockham’s Razor does not say, Prefer the simpler theory. Simplicity purchased at the price of explanatory adequacy is a fool’s bargain. An explanatorily adequate theory will posit some additional causes to explain the phenomenon in question, and Ockham’s Razor counsels us not to postulate more causes than are necessary to explain the effect.

Of course, reality is not always simple, so that a more complex explanation may in fact be the case. An amusing illustration of this fact is the Sesame Street book Sherlock Hemlock and the Great Twiddlebug Mystery, in which the shrewd detective concocts a fantastically complicated explanation to explain what are apparently the leftovers of a child’s birthday party. At the end of the story it turns out that his screwy theory was right!

Nevertheless, the point remains that Sherlock was not justified in postulating all his fantastic causes because he was multiplying causes beyond necessity. A more modest explanation was preferable. The assumption behind Ockham’s Razor is that by shaving away unnecessary causes, you are more likely to get to the correct explanation.

So in inferring to a Creator of the universe, it would be a violation of Ockham’s Razor to postulate more than one Creator, because one Creator suffices to explain the phenomenon calling for explanation (viz., the beginning of the universe).

So, in answer to your questions:

1. Define what is Ockham's Razor? A principle advising us not to multiply causes beyond what is necessary to explain the phenomenon in question.
2. How does this (scientific) principle or theory eliminate the need for extra gods? The question is misstated. The point is that there is no need for extra gods! One is sufficient to explain the phenomenon. Postulating any further gods would be gratuitous. If there were a need for extra gods, then Ockham’s Razor would not eliminate it or them.
3. How does Ockham's Razor prove the existence of One God? It doesn’t. It merely prohibits our postulating more than one in the absence of any evidence for them. We’re justified in postulating only as many deities as are necessary to explain the effect. So the kalam cosmological argument proves the existence of (at least) one deity, and Ockham’s Razor prevents us from positing any more.