March 14, 2018

## Does consciousness exist?

To answer the title question, of course consciousness exists.

Galen Strawson has an article in the New York Review of Books (h/t Brian Leiter):

I doubt that I am on Strawson’s list of deniers, but perhaps only because he doesn’t know who I am.

What is the silliest claim ever made? The competition is fierce, but I think the answer is easy. Some people have denied the existence of consciousness: conscious experience, the subjective character of experience, the “what-it-is-like” of experience.

Given that introduction, I would probably fit right in with Strawson’s deniers.

March 11, 2018

## Odds and ends about truth

In my previous post, I proposed a somewhat limited theory of truth.  Here I’ll discuss some of the issues that might arise out of that theory.

### What if there are no relevant standards?

According to my theory, we assess the truth of a statement based on accepted standards for evaluating that truth.  So what will happen if there are no applicable standards?

The simple answer, is that we cannot assess the truth of that statement.

This is not really a new situation.  When Gödel proved his incompleteness theorem, he showed that there are mathematical statements (arithmetic statements) cannot be proved true or false.  Such statements are often said to be undecidable.  If you use my suggested theory of truth, then there will  be undecidable statements in ordinary life, and not just in mathematics.

The existence of undecidable statement has not been any kind of calamity in mathematics.  And it is unlikely to pose a serious problem in ordinary life.

### What about the law of the excluded middle?

According the the law of the excluded middle (or LEM), a statement is either true or false.  However, LEM is usually considered a law or reasoning, rather than part of a theory of truth.  Mathematicians still use LEM in their reasoning, following Gödel’s incompleteness theorem.  And it does appear to cause any problems.  I would expect the same to be true in ordinary life.  If you use my suggested theory of truth, you will not have to give up LEM as part of your reasoning strategy.

### Changing standards

What happens if we change standards?

March 5, 2018

## A modest theory of truth

I have previously discussed some of the problems that I have with the so-called correspondence theory of truth.  In this post, I shall suggest my own theory.

I am describing it as modest, because it does not attempt to settle all truth questions.  The use of “true” in ordinary language is a mess, and my theory will not attempt to address all such use.  Rather, it is intended only for technical uses, such as in mathematics and science.

In my last post, I made a distinction between ordinary mathematical statements such as $3+5=8$ and the axiom systems (such as the Peano axioms)  that we use to prove those ordinary statements.  There is widespread agreement on truth questions about those ordinary mathematical questions.  But there is less agreement about whether axioms are true.  Mathematics can be done, without settling questions on the truth of the axioms used.

Coming up with axiom systems is also part of mathematics.  But when a new axiom system is offered, the main concern is on whether that axiom system is useful.  Whether the axioms are true is often not asked, perhaps because there isn’t a good way to decide.  Axiom systems are usually adopted on a pragmatic basis.  That is, they are adopted for their usefulness.

Something similar happens in science.  The ideal gas laws of physics are a good example.  Those laws are true only for an imagined ideal gas.  They are false for any real gas.  But although technically false, they provide a pretty good approximation of the behavior of real gases.  And that makes them very useful.  So, with the gas laws, we see important scientific laws that are adopted on a pragmatic basis, even though they might be technically false.

February 26, 2018

## Mathematical truth

While this post is about mathematical truth, it is really intended as part of a series of posts about truth.  The mathematics here will be light.  I am choosing to discuss mathematical truth because some of the distinctions are clearer in mathematics.  But I do intend it to illustrate ideas about truth that are not confined to mathematics.

Mathematicians actually disagree about mathematical truth.  But the disagreements are mostly peripheral to what they do as mathematicians.  So they usually don’t get into intense arguments about these disagreements.

### Philosophy

First a little philosophical background.

There is a school of mathematics known as Intuitionism.  This differs from the more common classical mathematics, in that it has a more restrictive view of what is allowed in a mathematical proof.  And, consequently, it has a more restrictive view of truth.  In particular, Intuitionists do not accept Cantor’s set theory.

The mainstream alternative to Intuitionism is usually called “Classical Mathematics“.

This post mainly has to do with truth in classical mathematics.  I mention Inuitionism just to acknowledge its existence and indicate that it is not what I will be discussing.

February 20, 2018

## What is truth?

Pilate famously asked the title question (John 18:38).  I expect people have been asking that question for as long as they have been asking questions.  For a good discussion of theories of truth, check the entry in the Stanford Encyclopedia of Philosophy.

Truth is a central concept in philosophy.  But I am not at all satisfied with the way that it is used.  Hence this post.

### Correspondence

If you ask about truth, you may be answered with the correspondence theory.  But the idea of “correspondence” is usually left unexplained.  I sometimes see statements similar to:

• A sentence is true if it corresponds to the facts.
• A sentence is true if it expresses what is the case.
• A sentence is true if it expresses the state of affairs.

The trouble with all of these, is that they seem to be roundabout ways of saying “A sentence is true if it is true.”  And that does not say anything at all.

Tags: ,
February 18, 2018

## Republican politicians kill people, with their failure to enact sensible laws

It is time to put the lives of our children ahead of the profits of the gun merchants.

It is well past time for politicians to stop accepting blood money from the NRA.

February 13, 2018

## On scientism

I’m never quite sure what “scientism” is supposed to mean.  It often seems to be little more than a strawman, or a punching bag used by some theists and some philosophers.

In any case, a recent blog post by Larry Moran:

drew my attention to an argument against scientism by Massimo Pigliucci.

I suggest you start by reading Larry Moran’s post.

### Pigliucci’s questions

In his argument, Pigliucci gives a list of questions that he sees as philosophical questions rather than scientific questions.  I shall quote the questions here, and then give my comments on them.

• In metaphysics: what is a cause?

Why should any scientist care about this?  Yes, causation is important to science.  But for science, we test causation be seeing what we can cause in our experimentation.  We attempt to narrow down causes.  And we tend to extrapolate that knowledge by way of predictions.  It is not at all clear that this has anything much to do with the metaphysics of cause.

• In logic: is modus ponens a type of valid inference?

Tags:
February 6, 2018

## Where philosophy goes wrong

Here are a couple of assumptions that philosophers frequently make:

• There is a certain way that the world is.
• There is information all around us, telling us the way that the world is.

By “philosopher”, I really mean human.  We almost all philosophize to some extent.

I see those two listed assumptions as mistaken.

### What is the mistake?

If your primary concern is getting around in this world, then the assumptions are not unreasonable.  The problem comes when we try to understand human cognition (or, roughly, what is it that the brain is doing?)

If we start with those assumptions, the ones that I consider mistaken, then there isn’t much for a cognitive system to do.  It just has to pick up the information that is all around us, and find out what that information tells us about the world.  That’s what leads to the idea of computationalism (“cognition is computation”).  And our experience with digital computers suggests that computation can be done in a way that is mindless and mechanical.

But a cognitive system has to be far more creative than that.

January 30, 2018

## Dennett’s book “From Bacteria to Bach and Back”

This post will be mostly rambling notes, rather than a review.

The subtitle of the book is “The Evolution of Minds” and that perhaps better describes what Dennett is trying to do in this book.  I started reading this book almost a year ago.  And then I put it down to take a break.  I have recently resumed reading, starting again from the beginning.

I mostly disagree with Dennett.  Yet I see this as an important book, particularly for people with an interest in minds and consciousness.

Dennett is, himself, some sort of heretic.  He disagrees with conventional view of the mind.  But his disagreement is not enough for me, nor is it is a direction that fits my views.

### Cartesian thinking

Dennett is critical of the dualism coming from Rene Descartes.  This is not particularly surprising.  Many philosophers and scientists have rejected dualism.  Descartes argued that the mind could not work in the mechanistic way that we see with human inventions (such as clocks, for example).  So he idea was that minds were constituted of an immaterial substance.

January 22, 2018

## Avoiding free will discussion

Jerry Coyne has posted a question on his blog site:

I’ll comment here, because I think I am banned from posting comments to Coyne’s site.

People avoid these discussions because they know, perhaps from experience, that such discussions produce a lot of heat but very little light.

Here’s the problem:

• There cannot be any credible evidence against free will.  For any such evidence would already demonstrate that the evidence was not freely obtained.  And if the evidence was not freely obtained, then it cannot make a credible case against free will.
• There cannot be any credible evidence for free will.  For we cannot rule out the possibility of hidden variables, so that what looks free is really determined.

And that leaves arguments at an impasse.

In my experience, arguments about free will are pretty much disagreements over the meaning of “free will”.

Tags: