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?

I think we tend to underestimate the importance of emotion in our lives. Yes, some emotions can be too strong and lead to poor reasoning. But our emotions are our evaluation system, and we need them for sensible reasoning. And it is because of our emotions that we care about getting our logic and reasoning right.

Logic and thought

Many people seem to have the idea that logic is the basis for thought. Thus we have a famous 19th century book by George Boole: “The laws of thought”. Alan Turing may have been thinking along similar lines when he published his 1950 paper “Computing Machinery and Intelligence”.

To me, this idea has always seemed mistaken. Yes, I can use logic in my thinking. But much of my thinking is far more diverse than the constraints of logic should allow.

We use language-like structures in our logic. But then we are a language species, so it is not all that surprising that we would emphasize the use of language-like structures. Still, there is a lot that seems illogical about natural languages, which again hints that thought is not based just on logic.


Artificial Intelligence (AI) is based on logic. This seems to arise from the tendency to equate thought with logic. If you equate thought with logic, then you are likely to think of intelligence in terms of logic. So when it was shown that computers could do logic very well, I guess it was to be expected that some people would look toward creating artificial intelligence.

AI never appealed to me. That computers could do logic, only showed that logic is itself mechanical. But I never thought of intelligence as being mechanical. It has always seemed that we use intelligence to get around the limits of mechanism. So I’m one of those people who sees AI as a problem that is half solved. They only have the “artificial” part of it working.


We see something similar with IQ tests. Those tests tend to emphasis those aspects of intelligence that use logic. And, for sure, we do see examples of intelligence in the use of logic.

From my perspective, the way it works is this. Somebody constructs a logic model of a problem. And then the problem is solved using logic. But it has long seemed to me that the real intelligence goes into the construction of the logic model, rather than in using the logic within the model. We tend to credit logic, when that isn’t the actual source of intelligence.

Intelligent Design

We also see something similar within the Intelligent Design (ID) movement. The ID people look at biological systems, and don’t believe they could have arisen be exclusively mechanical means. So they propose that there must have been an intelligent designer who came up with the whole system.

They are thinking in terms human intelligence and human use of logic and planning. So they emphasize intellectual aspects of intelligence.

What they fail to see is that there is intelligence throughout the biosphere. Of course, plants and primitive animals don’t talk, so we cannot use intellectualist measures (such as IQ) to assess their intelligence. But if we look at their behavior, at how they respond to conditions in their environment, then we can see that there is some intelligence throughout all of the biological world.

Those are my musings for this week.

2 Comments to “Musings about logic”

  1. Ever since I read Damasio, I’ve realized that Spock was a bit of a caricature, and the way they portrayed the whole logic/emotion thing was bogus.

    Liked by 2 people

  2. “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.”

    Funny and insightful.

    Liked by 1 person

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