Archive for July, 2021

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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