Science works; ergo God

by Neil Rickert

I obviously do not believe what is suggested by the title.  That title is my simplified way of describing what vjtorley has recently posted at the Uncommon Descent blog.  The tl;dr form of the title, as used by vjtorley, is:

The UD post uses a method of argument that we mathematicians refer to as Proof By Exhaustion.

There are actually two different versions of “proof by exhaustion”.  The main version is where one proves a result by exhausting all possibilities.  It is much like a case statement in a computer program.  That’s the version that is defined by the linked Wikipedia page.

The other version of “proof by exhaustion” is the one used by vjtorley.  That is where the argument is so tediously long, that you are exhausted by the time that you have finished reading it.  In fact, you are so exhausted, that you were too tired to notice all of the glaring holes in the argument.

A brief synopsis

Here’s a brief synopsis of the argument that vjtorley offers:

  • Science works by induction;
  • induction is absurd;
  • ergo God.

That’s pretty much the entire argument, cut down to a sensible size.

I’m a critic of inductionism (the thesis that induction is a key scientific method).  So, naturally, I don’t think much of that argument.


A brief explanation of the term “induction” is in order.  Induction is said to be typified by examples such as:

  • All the many ravens I have seen were black;
  • therefore all ravens are black.

I’ll sometimes refer to this as philosophic induction, to distinguish it from other kinds of reasoning where “induction” is also mentioned.

Science does use statistical hypothesis testing, and this is sometimes described as an inductive method.  However, I see that as deductive.  Mathematics is used to deduce a conclusion.  The conclusion from such a statistical inference is a probability distribution for likely outcomes.  In particular, the conclusion is not a simple fact.  While I am critical of claims about the use of induction, I fully accept the proper use of statistical inference.

The argument

Early in the post, we read:

In science, the term induction is commonly used to describe inferences from particular cases to the general case, or from a finite sample to a generalization about a whole population.

That already seems wrong.  That’s what I read in philosophy, but not in science.  In a forum debate, I once asked an opponent to cite some published scientific research papers, where the paper asserts that induction was used.  My opponent admitted it unlikely that there were such published research papers.

Vjtorley then goes on to criticize opposing views, such as those by the authors that he mentions in his title.  They argue that animals seem to get along just fine without using induction.  They manage by use of pragmatic methods — doing what seems to work.

In response, vjtorley writes:

Second, Loftus fails to differentiate between procedural knowledge (“knowing how”) and declarative or descriptive knowledge (which can only be expressed in propositions). It is obvious that animals need to know how to obtain food or to mate, or they wouldn’t have survived. Some animals have also learned certain techniques that promote the survival of the population, on a trial-and-error basis. But science isn’t just a collection of techniques; it’s an organized body of facts, unified by theories which purport to accurately describe the world.

That’s an all to common misunderstanding of science.  It’s the procedural knowledge, the know how, that is the bulk of scientific knowledge.  Much of what vjtorley calls “declarative or descriptive knowledge” is just an attempt to present part of that know how in a descriptive form.

In effect, vjtorley is putting the descriptive knowledge on a pedestal, and insisting that it could not work by itself.  Well, he is right that the descriptive knowledge could not work by itself.  But it is not a matter of needing God.  What it really needs is all of that scientific know how that stands behind the descriptive accounts.

I’ll call that a fail for the argument he presents.

The linked video

The UD post includes a link to a video, explaining induction in science.  I have some disagreements with that, too.

The video suggests that the idea of using induction in science comes from Francis Bacon.  However, what Bacon described is very different from the philosophic induction being discussed here.  It is often called Baconian induction.  It suggests teasing apart the various antecedents of an event, and testing which are really part of the cause.  Science does use Baconian induction.  But the evidence for use of philosophic induction is lacking.  If philosophic induction is supposed to be based on simplifying Baconian induction, and getting to the essence of what makes it work, then I’m afraid that philosophy has thrown out the baby and kept only the bathwater.

The video uses Hooke’s law to illustrate induction.  I remember when I first heard of Hooke’s law in a high school physics class.  It was already clear to me, at that time, that Hooke’s law described an ideal elastic object.  It did not claim to describe reality.  It was an idealization, used to mathematically model things such as springs.  It was already clear that Hooke’s law was likely false for anything real, but was a useful approximation for some real things, but not for others.

We do not get laws like this by induction.  We get them by bold assertion, followed by pragmatically testing for usefulness.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: