In Defense of Evidence

~ analyticalcortex

Neil deGrasse Tyson recently made a tweet:

This 21-word tweet caused Sociologist Jeffrey Guhin to write an article denouncing him on the website Slate.

This article makes some good points, but it also has serious flaws. First is the straw man argument it puts up – “Science should also teach us how to live, pointing us toward the salvation religion once promised.” This is not what Tyson said, nor would he say something so foolish. Tyson is not endorsing scientism.  No rational scientist would. Tyson’s tweet was focused on making sure policy should be tied to evidence. Guhin makes no argument against using evidence to decide policy, completely missing Tyson’s point.

Guhin points out several flawed beliefs that have come under the name of science in human history – phrenology, eugenics, scientific racism. These examples have nothing to do with evidence. The latter two concepts do not qualify for science as we currently define the term – they are policies, not hypotheses. Furthermore, there is no evidence to support any of these ideas. Therefore, following Tyson’s tweet, there is no rational reason to follow them. Guhin claims that “Part of the problem here is that nobody really knows what science means.” In reality, I would argue that most scientists follow the definition of science put forth by Karl Popper: science represents the testing of falsifiable hypotheses.

The author continues to talk about logical fallacies like motivated reasoning. And yes, humans individually are prone to many types of logical fallacies. That includes scientists as well. But science as a whole – the community of scientists – functions well as a self-critical and self-correction entity. Bad hypotheses, like the Piltdown Man, are eventually discovered and discarded. Even good hypotheses can be discarded. Newton’s theory of gravity works well until Einstein started thinking about gravity on a grander scale. That’s what makes science different from all other belief systems. It’s the weight of the evidence that matters.

Guhin finished with an emotionally charged statement, saying “Scientists can’t tell us if it’s right to kill a baby with a developmental disability, despite how well they might marshal evidence about the baby’s relative life or her capacity to think or move on her own.” Again, no rational person would say that science is to be a guide to morality. But science can give us evidence about our world, and, as communities of people, we can weigh the evidence along with our personal views of morality, to decide what is wrong and right. If we were to discard evidence, as Guhin seems to be implying, we would only be acting with uninformed opinions. That’s a step that would take us back to the Dark Ages.

Tweets on Twitter are too short to fully represent a person’s full philosophy or nuanced way of thinking. I consider it quite irrational to take a tweet, assume a meaning, and write a rant against it. A much more rational response would be to engage the person in dialogue and find out what they mean. Such a dialogue may not give you a click bait headline to make money, but it would allow a constructive exchange of information.

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