Monday, August 6, 2012

Reality is not a democracy

In a rather bizarre article trying to argue that plants aren't alive (yes, really), Henry Morris III, CEO of The Institute for Creation Research provides a very nice example of an Ad Populum. An ad populum is an appeal to popularity in which one argues that because a certain belief is widely held or popular it must be true. That this kind of reasoning is fallacious should be obvious: just because a bunch of people believe something, doesn't make it true. Reality is not a democracy. Here is the ad populum:
If that were the only battle to fight, the scientific accuracy of the creationist model would be rather easy to demonstrate. In spite of the generations-long effort of the academic world to foist evolutionary naturalism on the world, 46 percent of the U.S. population still believes that “God created human beings in their present form at one time within the last 10,000 years” (Gallup poll released June 1, 2012). Intuitively and observationally, people “know” that plants and animals are not the same and that human beings are vastly different from everything else on the planet.
There are a number of fallacies in this passage besides the ad populum, but let's deal with that first. Here, Norris is trying to argue to that because many (though less than half) Americans don't believe in evolution this is somehow evidence of the falsity of that theory. Again, just because many people believe something, that doesn't make it true. In this case, it seems clear that 46% of Americans are just wrong.

Furthermore, this fact about popular opinion doesn't actually support Morris' thesis that plants are not alive. Even if 46% of Americans don't believe in evolution, I imagine that if you polled these people they would all think that plants are alive. The opinion of people about the truth or falsity of evolution tells us nothing about their opinion on whether or not plants are alive. This is a good example of a non sequitur.

Lastly, we can see a good example of a straw man in the last sentence. I (and I imagine most evolutionary biologists) would certainly agree that it is obvious that plants and humans are different. Just look at them.
An image of the DC comic book character Swamp Thing.
Maybe not this guy.
However, these radical differences don't tell us anything about common descent. In fact, evolutionary theory does a very good job of explaining how the diversity of life we observe on our planet all descended from a common ancestor. To claim otherwise is to misrepresent the claims of proponents of evolution.

h/t to Pharyngula


  1. First of all, I do know the evolutionary theory explains scientifically many processes in nature. This epistemological fact is undeniable. But after laughing my ass at Morris claims I find this:

    "In fact, evolutionary theory does a very good job of explaining how the diversity of life we observe on our planet all descended from a common ancestor."

    Correlation between two variables does not automatically imply that one causes the other. Means, it doesn't matter if evolutionary theory does a good job at it. It still doesn't imply, as undeniable truth, we all descended from a common ancestry. That's why it's called a "theory" and not a "law".

    What you just did was a "Cum hoc ergo propter hoc" after delivering a synthetic judgment.

    1. Thank you very much for your comment! However, I am not sure I buy your criticism. I never suggested that correlation implies causation, I merely noted that evolutionary theory does a good job explaining everything we would want explained by it. Does this mean evolutionary theory is 100% objectively true? No, but it is the best explanation we have, and until someone comes up with a better explanation, it seems reasonable to provisionally endorse evolutionary theory. Certainly from a scientific perspective everything we have learned about our world in the past 150 years supports the view that we all descended from a common ancestor through natural processes. We may find out something tomorrow that calls this into question, but until then, we should probably stick with the best theory we have.

    2. In addition, my comment was meant as a reply to the straw man in the last sentence of the quotation which seemed to suggest that evolution can't explain why humans and plants are different. The argument runs something along the lines of, "If we all descend from a common ancestor we should all look the same. We don't all look the same. Therefore, we didn't descend from a common ancestor.") This argument is not sound because evolutionary theory explains why the first premise is false. There is a way to account for common descent and diversity, something which the theory of evolution provides. This fact combined with the mountains of evidence for the theory collected in the past 150 years gives us a very good reason to endorse the theory of evolution.

  2. English is not my native language and sometimes I'm unable to explain myself more clearly. Therefore, in other words:

    You're claiming that we know we all descend from a common ancestor because the evolutionary theory does a very good job explaining life diversity and it's origins.

    1. I am not sure what else it would mean to know something. If all the evidence we have collected supports the theory; if the theory makes accurate predictions and allows us to accomplish goals and understand the world more effectively than we could without the theory, then why wouldn't we endorse it? Of course there is always the possibility that some new information could come along to falsify the theory, but until then I see no reason not to accept the theory.

    2. I'm just picking a possible fallacy in your argument, which btw is pretty solid. That's all.

      I do endorse the theory of evolution and agree with your conclusions. Nevertheless, I tend to play devils advocate many times. The sole purpose is to check possible logical fallacies in scientific argumentation. Believe me, there are many scientists that demonstrate a fundamentalist attitude and many times don't check themselves in regards to their own claims.

      As I said before, of course the theory of evolution is the best explanation mankind has ever achieved in regards to know the origin of life. But still, and until it's completely proven, we can't use it to make absolute assertions. The logic is very solid but one must be careful and use the right words to support the claims.

      Thanks for your time and responses btw !

    3. It seems we are in general agreement. I would just add that the theory of evolution can never be completely proven. All science can ever give us is provisional confidence in a theory pending the discovery of new evidence.

    4. Agreed. That's the beauty of science. It always pushes us beyond our limits out of curiosity until we reach THE answer. But to achieve perfection, there must be always a way to question itself or else its claims can become dogmas.

      Question yourself so your ideas don't loose focus. Therefore, science won't become a belief system but a way to find truth in our reality.

      Philosophy plays a huuuuge roll in this task, acting like a self controlling system. In this aspect, philosophy has an undeniable contribution to science, where argumentation logic and validation delivers this purpose perfectly.


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