Archive for ‘My Philosophy’

July 25, 2021

The world is not a logical place

by Neil Rickert

Let’s start with some definitions:

  • logical: in accordance with the laws of logic;
  • illogical: contrary to the laws of logic;
  • alogical: the laws of logic are not applicable.

My title is suggesting the last of those — that the laws of logic are not applicable to the world.

Of course, we do use logic. But we have to do some preparatory work to make it possible to use logic.

A logical world is a world of immutable objects. I’ll refer to those as “logical objects”. When doing mathematics, the numbers are examples of logical objects. In logic, we use the idea of “identity”, where A and B are identical if those are really just different names for the same logical object. So 3+1 is identical to 2+2, because those are both ways of referring to the same number 4.

In the world we live in, there are no immutable objects — see my earlier post about change. And what we mean by “identity” and “identical” can sometimes be confusing. Those are because our world isn’t really a logical world.


How do we deal with this situation? We categorize. That is to say, we divide the world up into parts (i.e. categories), and treat those categories as if they were logical objects.

Some people think of categories as collections of individual objects. I prefer to think of categories as arising from carving up the world into parts. What we think of as individual objects are themselves categories. We think of a person as an individual. But a person changes. The atoms which constitute that person today will soon be gone, and replaced by different atoms. A person’s appearance changes due maturing and aging processes. But we see these variations as the same person, because when we carve the world up into categories we place the variations of that person into the same category.

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July 19, 2021

Mental confusion

by Neil Rickert

I decided to have a little fun with the title, so it might be a tad misleading.


There is a thesis going by the name “mentalism” which is common in philosophy of mind. And there are things about mentalism that I find puzzling. So that’s the topic for today’s post. In his book “Psychological Explanation”, Jerry Fodor defines “mentalism” as the rejection of behaviorism. A large part of his book is engaged in criticizing Gilbert Ryle’s “The concept of mind”.

A side note. I looked up Fodor’s book in preparation for writing this. Amazon lists it as a paperback for $1500. Wow! I read it some time ago, borrowing from the university library. It is surely not worth $1500. (Amazon does also list less expensive used copies).

For myself, I guess I am really a behaviorist. And that may be why I find mentalism to be puzzling.

I take the term “mental” as having to do with the mind. So thinking would count as a mental activity. But it gets more complicated,, because some people talk about unconscious thinking. I doubt that there is any such thing.


I already have problems with the word “belief”. The verb “to believe” is straightforward. No doubt there are many statements that I would believe. But I never sure what is a belief. The noun “belief” used as an abstraction to refer to the concept of believing seems unproblematic. But that is not how “belief” is used.

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July 11, 2021

Against semantic externalism

by Neil Rickert

Sometime, I think it was back in the 1990s, I was involved in an online discussion of AI. I casually remarked that meanings are subjective. To my surprise, somebody gave me an argument against that. The basic idea was that language is shared in the community, and therefore meanings must be shared, so could not be subjective.

I remained unpersuaded, so I was pointed to Hilary Putnam’s paper “The meaning of ‘meaning'”, where Putnam argues that “meaning is not in the head.”

This post is about why I disagree. The expression “semantic externalism” is commonly used for the view expressed by Putnam and others, that meaning comes from the community rather than from the individual person.


My own experience suggests that people disagree a lot about meanings. They perhaps believe that they are disagreeing about logic or about evidence, but often the real disagreement is about meanings. That’s where I get the idea that meanings are subjective. As an example, look at arguments about “free will”, where disagreements over whether we have free will often look more like disagreements over what we mean by “free will”.

Of course, it is quite possible — and even likely — that what I mean by “meaning” is not the same as what Putnam means by “meaning”. But, if that is the case, then our own disagreement about the meaning of “meaning” is evidence that meaning is subjective.

Twin Earth

In his argument, Putnam introduces the idea of “Twin Earth”. Here, Twin Earth is a planet much like earth, with similar people. And what’s in the heads of Twin Earthians is said to be the same as what’s in the heads of us earth people. But, on Twin Earth, the liquid that they call “water” actually has a chemical composition of XYZ instead of H_2O. Yet the Twin Earthians talk about it as “water” much as we would for H_2O.

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July 5, 2021


by Neil Rickert

sThere’s an old saying: “The more things change, the more they remain the same.” But it seems to me that you could also say “the more things stay the same, the more they change.” Or, as people sometimes say, “We are in a world where the only fixture is that everything is changing.”

We live in a world of change. And that’s the idea behind this post.

In the beginning

According to Genesis, it all began with the creation of the earth as a solid foundation. But, since then, Copernicus, Galileo and others have persuaded us that the earth is actually adrift, moving around the sun. Later astronomers found that the sun itself is adrift, going around the Milky Way galaxy. And the Milky Way galaxy, much like millions of other galaxies, are adrift in the cosmos.

Once we understand it, this is not particularly surprising. If you set a boat in the ocean, you expect the boat to drive with the tides, currents and winds. You can stop the drift by anchoring the boat to the continental shelf. But then we have learned that the continents are themselves drifting.

It seems that everything is adrift, and nothing is fixed.


If we look to science, we see an attempt to give us stable measurements. For example the Newtonians fixed time based on the rotation of the earth, and they fixed length based on a fixed platinum rod in Paris. But these are all somewhat arbitrary choices.

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June 28, 2021

Musings about logic

by Neil Rickert

Logic has always come naturally to me. Perhaps that is why I went into mathematics. However, some people find logic to be quite difficult. Even some very creative people can have difficulty with logic. I guess it is just as well that we are all different and can benefit from that diversity.

For me, as a mathematician, the term “logic” is used for inference involving the strict following of rules. However, people seem to have varied ideas about logic. So this post will be a somewhat rambling stream of comments (musings).


It is sometimes said that if the only tool you have is a hammer, then before long every problem begins to look like a nail. And if the only tool you have is logic, then every problem begins to look like a proposition.

Logic is not the only tool that philosophers use. But, in my opinion, they do seem to give it too much emphasis. And, perhaps as a result, they do tend to put too much emphasis on propositions. We see this when they define knowledge as “justified true belief”, so as to have a propositional account of knowledge. But it has always seemed wrong to me. As I see it, the knowledge of a plumber is in his ability to fix the pipes; he does not need to give eloquent speeches about pipes.

Similarly, philosophers of science often describe scientific theories as belief systems. But this, too, seems wrong. A theory is much more a system of research behaviors than a system of beliefs.

Mr Spock

In the Star Trek series, Mr Spock was notable because he did everything with logic and avoided emotion. But here’s my question: if there was no emotion, why would he even care whether he got to logic right?

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June 21, 2021


by Neil Rickert

I skipped posting last week. I had planned to post about knowledge and belief, but decided to skip that post.

Conventionalism is interesting, in part because much of our life seems to depend on social conventions. And, in part, because philosophers seem to be strongly opposed.

According to Wikipedia, “Conventionalism is the philosophical attitude that fundamental principles of a certain kind are grounded on (explicit or implicit) agreements in society, rather than on external reality.”


It is usually agreed that a social convention is an agreement, perhaps implicit rather than explicit.

The rule that we should drive on the right side of road is often mentioned as an example of a convention. In some parts of the world, including Australia (where I grew up), people instead drive on the left side of the road. That there was a choice between driving on the left, or driving on the right, illustrates why conventions are said to depend on arbitrary choices. But those two choices (left vs. right) are not the only options. For example, there could be a system where people drive on the left on even numbered days and on the right on odd numbered days. This would be more confusing, with probably more accidents. But it serves to illustrate that there is often a degree of pragmatism in our choice of convention. Saying that a convention is an arbitrary choice does not rule out the involvement of pragmatism in the making of that choice.

Poincare proposed conventionalism for geometry. In his view, the axioms of geometry derive from our measuring conventions. I agree with Poincare on that.

Hilary Putnam argued against conventionalism in “The Refutation of Conventionalism”. One of his arguments was that under conventionalism there could be no matters of fact. I just measured the height of my desk as 74 cm. That’s a matter of fact which depends on the measuring conventions which define the centimeter. From the way that I look at it, all facts are relative to the conventions that we follow when observing those facts.

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July 31, 2020

My views on science and relativism

by Neil Rickert

When I posted a review of “Science and Relativism” last week, I indicated that I would follow up with my own views on that topic.  So here it is.

When Kuhn’s “The Structure of Scientific Revolutions” came out, I thought it painted a somewhat better picture of science than what has been traditionally presented.  I didn’t agree with everything that Kuhn said, but I did like that he was challenging the traditional picture.

When, many years later, I read Feyerabend’s “Against Method”, I thought it a pretty good read.  I took Feyerabend to be poking fun at traditional philosophy of science, and I saw that as a good thing.  When he suggested that voodoo might work as well as science, I was not sure whether he was serious — and I’m still not sure.  In any case, I did not see him as a threat to science.

Where philosophy goes wrong

In my opinion, much of what people see as criticisms of science are really a reaction to the idea (from epistemology) that knowledge is justified true belief.  As best I can tell, most scientists and most mathematicians see knowledge as distinct from belief.

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April 29, 2020

The scientific and manifest images

by Neil Rickert

As a followup to my previous post, I’ll note that Dan Kaufman has posted a second round in his proposals for metaphysics:

As background, I’ll note that I am sitting at my desk.  According to the manifest image, my desktop is solid wood.  According to the scientific image, my desktop is mostly empty space surrounding a sparse array of atoms.

The scientific image is how physics sees the world.  The manifest image is closer to how we see the world.  But sciences vary.  Biologists are concerned about individual organisms.  And those belong in the manifest image, rather than in the scientific image.  Likewise, most of the concerns of psychology fit better with the manifest image.

In my view, philosophy (by which I mean academic philosophy) is mainly oriented toward the scientific image.  And, in my opinion, it should be more oriented toward the manifest image.  I think that’s also how Dan Kaufman sees it, but perhaps I am misreading him.  Please go read his post to see what he says.

Where I come in

A little background about myself.  I started studying learning (or how humans learn) in the 1980s.  And I quickly found myself disagreeing with philosophers.  I imagined myself to be a solitary animal or organism on some planet, with little or know innate knowledge of the planet.  And I had to work out ways of learning about that planet.

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April 25, 2020

Thoughts about metaphysics

by Neil Rickert

Hmm, it’s been quite a while since I last posted anything to this blog.

Dan Kaufman is rethinking metaphysics, as indicated in a recent post:

Judging by the relatively small number of comments, I don’t think there’s a lot of enthusiasm among readers.  But I will be looking forward for continued posts on this topic.

In agreement with Dan, I do want to see some rethinking.  And that’s why I started this blog.

I’ll use this post to give some of my own ideas on the topic.  I expect that some of them are very different from Dan’s ideas.

Basic realism

I am assuming some sort of basic realism.  That is to say, I assume that there is a reality which is human independent.  And we interact with that reality.

I’m calling this an assumption, because I see no possibility of proof.  But it does make clear that I reject Berkeley’s idealism.  I don’t think anything important depends on this assumption.

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January 18, 2018

Generalization in science

by Neil Rickert

According to most treatments of philosophy of science, or at least most of those that I have looked at, science advances by means of inductive generalizations. Inductive generalizations are often assumed to be the basis for scientific laws (such as laws of physics).

To me, that seems wrong.  I do not see the evidence that science is using induction.

I can agree that there are generalizations in science.  But it does not seem to me that they are inductive generalizations.


First an example of induction, to illustrate what is meant by the term.

All the many crows that I have seen are black.  Therefore all crows are black.

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