Thursday, November 26, 2015

Logical fallacies

Stephen Hawking
In the previous article I mentioned that advocates of materialistic scientism often fall in logical fallacies, but usually do not notice, probably because their knowledge of philosophy is not deep enough. Moreover, they often despise philosophy, not realizing that logic (which is a part of philosophy) aims to analyze the way we think, and that, without logic, science loses its supporting base. So, Stephen Hawking wrote at the beginning of his book, The Grand Design:
Philosophy is dead ... Scientists have become the bearers of the torch of discovery in our quest for knowledge.
And starting there, he proceeds to make philosophy in a popular science book.
In my discussions with supporters of materialistic scientism, I’ve often had to tell my opponents that they are committing a logical fallacy. Generally they are reluctant to admit it, but when I explain it in detail, they finally do (I guess, because usually the discussion ends there). By this I do not mean to imply that I never fall in logical fallacies, because we are all human, but at least so far, no one has shown me any. Of course, it is possible that I have fallen in them and the person who was debating with me did not notice.

In this post I will consider three of the more frequent logical fallacies in these debates:
  • Begging the question: asserting that something is obvious, that it has been proved, without providing arguments. This also happens when things like this are said: Biological evolution is not a hypothesis, it is a fact. This statement is not true. Evolution is a very well-tested hypothesis, with many arguments in its favor from disciplines such as comparative anatomy, embryology, paleontology, biogeography and molecular biology, but it is not a directly detectable scientific fact.
  • Straw man: mounting an argument against a proposition, but actually directing it against a different proposition, and then trying to pass it as the same as the proposition that you want to refute. An example of this is the classic atheistic argument against the existence of God, based on the problem of evil:
1.      An all-powerful God can do anything.
2.      A good God cannot accept evil.
3.      In our universe there are lots of evil, therefore our universe cannot have been created by an all-powerful good God.
Once, when I was arguing with a scientifistic materialist who offered this argument to me, I opposed the following counterargument:
To reach this conclusion, you need to prove that it is logically possible to create a world completely free of evil.
To which he replied:
I define all-powerful as the capacity to do everything, even logical impossibilities.
And I said:
Richard Dawkins
Then your argument is a textbook case of the straw man fallacy:
  a.    You define all-powerful in a different way as believers define it.
  b.    You prove that an all-powerful good God based on your definition cannot exist.
  c.    You apply this conclusion to our definition of an all-powerful God, which excludes that God can make logical impossibilities.
This was the end of the discussion.
Another famous example of the straw man fallacy is the famous ultimate 747 argument, used by Richard Dawkins to prove that God cannot exist.




  • Ad hominem: this is the most common fallacy. It consists in disqualifying the opponent, rather than arguing his position with rational arguments. I don’t remember how many times I have been told something like this:
You say that because you are a believer.
I answer this by showing the fallacy and adding:
This fallacy is bidirectional, for there is nothing to prevent me to answer as follows:
You say that because you are an atheist.
But as that would not be a real debate, but a simple exchange of epithets, if you have no other arguments, it is best to end the discussion here.
Usually, this ends the discussion.


Manuel Alfonseca

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