Sunday, April 20, 2008

Occam's Razor

I recently engaged a fellow blogger (Orthoprax) in a rather lengthy and tedious argument. I asked him how he knows that God, if He exists, is one. He replied that God is postulated to be singular on the ground of parsimony. He stated that it is a simpler hypothesis to assume that God is one rather than more than one. Needless to say I was unsuccessful in my attempts to convince him otherwise. At one point he called my attempts “annoying” and repetitive.

Nevertheless, I was intrigued by the concept of parsimony or Occam’s Razor. So, I will make another attempt on my blog, where the neighborhood is a bit friendlier.

First, Parsimony, or Occam’s Razor is a logical principle, which states the following:

All else being equal, the simplest hypothesis proposed as an explanation to a given phenomenon is more likely to be the true one among alternate hypotheses.

This is a rather useful principle and is frequently used in scientific thought and in everyday decision making. Let me give some examples:

Suppose you wake up one winter morning and notice that the ground is covered with snow. You wonder what happened at night when you were sleeping. The possibilities are as follows:

  1. It snowed last night and the ground was covered with snow.
  2. A group of professionals with snow making machinery came in when you were sleeping and worked all night to fill the streets with artificial snow.
  3. It started snowing last night, but the snow fall was brief. Following the brief period of snow, the professionals came and augmented the snow with powder.

If you had no other data than the information given to you above, which choice would you consider more likely?

You might say that choice #1 is more likely since it only assumes the occurrence of a common and natural process, namely the occurrence of snow in winter time. It is simpler to assume that the ground would be covered by natural snow than man made snow, given that we routinely see natural snow in the winter. You might say that choice #1 is more parsimonious, and thus more likely to be true.

But suppose now that you lived in Southern California. Here, the occurrence of snow is much less common. It is very uncommon to see snow in the Southern California. Perhaps in anticipation of an upcoming motion picture filming, a crew equipped with snow making machinery really made snow to cover your street. Given the information of your location makes possibility 1 and 2 somewhat equally parsimonious. Possibility #3 is not parsimonious since it assumes both snow in a warm climate and existence of machinery. All else being equal, possibility #3 is not parsimonious.

What we learn from the above example are:

  1. Hypotheses which make the least number of assumptions are more likely to be true, all else being the same.
  2. When further information is provided, the parsimony of a given hypothesis is altered.

Now let’s consider one more example:

Suppose I wish to know how many inches of snow are on the ground in place X in the winter. The choices are:

  1. 1 inch
  2. 2 inches
  3. 3 inches

Having no further information, and knowing nothing about place X, can we decide which is the most likely answer? Can we by parsimony argue that choice #1 must be the correct answer since it is the simplest? If not, why not?

Notice here, that the choosing “1 inch” of snow is not any more parsimonious than the other choices.

Let’s see another example:

Last night I went to a party; guess how many people were there:

  1. 5
  2. 10
  3. 20

Here, again, note that we can not give a reasonable guess based simply on parsimony. Any one guess is as good as any other.

Now, one final example:

I own an elaborate watch. How many people have constructed it?

  1. 1
  2. 5
  3. 10

Here, again, notice, that without any further information, we can not guess on the number of people which have made my watch. We can make an educated guess, saying that from what we know usually a team of workers come together to make watches, but this draws from extraneous information. The point is that parsimony does not allow for making this choice.

Now, for the question at hand:

HOW MANY GODS ARE THERE? The choices are:

  1. One
  2. More than one.

I have given an example of how we can use the concept of parsimony to make choices, and I have given examples of circumstances where we can not. Now, to which of these examples does this question belong?

Is it parsimonious to assume that God is one? If so, why?

This fact is that there is no basis to assume that God, if he exists, is one!