Wednesday, February 12, 2014


This article is part of a series of articles on skepticism, science, and topics like paranormal/supernatural/religions which would greatly benefit (aka. disappear) from skeptical and scientific inquiry.

This is possibly the most important, most fundamental subject that I will ever write on. And that's exactly why I will fail. A quote from Antoine de Saint-Exupery says that perfection is achieved not when there's nothing more to add, but rather when there's nothing more to remove. But the problem is that perfection and popularizing are different. So, I'll add explanations and illustrations and make it less perfect. But by doing so, I'll try and make it understandable. And I'll probably come back to this article 100 times and edit it 100 times to tweak, rephrase, prune, add, patch and fix. In other words... bear with me and if something seems amiss, let me know!

Making sense of the world

There are various ways to make sense of the world we live in, and build knowledge. The most basic way is the one we have developed through natural selection and which other animals also possess: we observe what happens around us and we draw conclusions or we instinctively respond to what happens in our environment. It works to a certain extent but it has limits. Here's an example: you walk in a street of London and you hear the sound of hooves behind you ; you don't expect a zebra! You expect a horse. But sometimes it will be a zebra, and you've been fooled by your intuition.

I mentioned something similar in the article about pareidolia: for survival reasons, we evolved an intuition that makes us prone to overestimating danger and to react quickly to imminent danger. The result of that: our intuition is often mistaken and it is especially bad at estimating long term consequences.

Our brain has also evolved in an environment where we have to deal with finite quantities. As long as we manipulate quantities around 6, 7 or 8 our mental abilities can cope. A famous example of this is when you give people a list of words to memorize in a limited time and 7 is the average number of words that people successfully recall. That is to say our intuition and our mind are flawed tools. They're efficient in a number of specific situations but they're not reliable.

Another tool available to us to make sense of the world is logic. Logic is an intellectual construct which is incredibly powerful. Since it is an intellectual construct, it is not intuitive ; not in its details at least. Therefore it takes time to master.

Logic is the connection of premises in order to obtain conclusions. The age-old example is:
Premise 1: All men are mortal
Premise 2: Socrates is a man
Conclusion: Socrates is mortal

This is a very simple, very limited example but logic is what binds the conclusion to the premises. And most important of all: if we hold the premises as true, then logic binds us to admit the conclusion as being true too.

Ultimately, logic is the most fundamental tool to understand reality and empower us to build even more understanding and granting us the power to act.

Logic allows us to understand that identical causes will bring about identical consequences. This gives us the capacity to predict outcomes just by looking at the initial conditions. And that is the root of philosophy, knowledge, mathematics, science, set theory, electronics, etc.

The limits of logic

Sometimes we think we are using logic but we are only using what people call "common sense", which is a misleading term more akin to "opinion" than it is to "logic", because it is only based on cultural cues.

Logical fallacies, or errors to apply logic, are also a common pitfall. Logical fallacies are so numerous and lead to such horrors of thought and behavior that they'll deserve several articles and will need to be mentioned in topics related to religion, conspiracy theories, pseudosciences, science and skepticism.

Erroneous premises: sometimes we use valid logic but our premises were just wrong. Here's an example:

  • premise 1: men are immortal
  • premise 2: Socrates is a man
  • conclusion: Socrates is immortal
  • The logic is absolutely valid but the conclusion is wrong (since Socrates died) because the 1st premise is wrong.

The limits of our understanding and knowledge: there are specific fields of science where the laws of nature reach extreme cases where our knowledge breaks down. Such is the case for example of our understanding of the earliest moments after the Big Bang.


Logic is the fundamental building block of human knowledge and understanding. How well or poorly it is employed is a different subject altogether but logic itself is necessary to extract meaning from chaos. Logic is not the conclusion but the mechanism by which we draw conclusions from initial statements.

Anything that has no logic is chaotic. Therefore anything that has no logic is unpredictable or unreliable. That's why logic is the end-all be-all of human knowledge and rationality. That's also why there is a rational basis for rejecting the illogical claims of religions, pseudosciences, and other forms of quackery, but these will be treated in separate articles.

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