While reading through Michael Shermer's enjoyable book How We Believe: Science, Skepticism and the Search for God (New York: Henry Holt, 2000) I came across the following passage:
"Doubt is good. Questioning belief is healthy. Skepticism is okay. It is more than okay, in fact. Skepticism is a virtue and science is a valuable tool that makes skepticism virtuous." (xxv)
There is just enough truth in this statement to make it dangerous.
First problem. Shermer says "doubt is good." I reply: "Sometimes. But sometimes doubt isn't good."
And when might that be?
For example, I believe the following proposition:
"It is wrong to inflict suffering on others simply because doing so is pleasurable to the perpetrator."
Would Shermer say without qualification that doubt of this proposition is good? I assume not. (If he would commend doubt of that proposition then I would simply shift ground by arguing that he ought not commend doubt of it. And I suspect most of you would agree with me.)
So clearly it is not always good to doubt.
We can illumine the complexities by considering the following conversation I had with my daughter the other day:
Daughter (while reading National Geographic for Kids): "Hey, it says here you can't tickle yourself."
Me: "That's true."
Daughter (puzzled): "But Jenny at school said she can tickle herself."
Me: "Who you gonna believe? Nine year old Jenny or National Geographic?"
Daughter (sheepishly): "National Geographic."
What can we learn from this exchange?
To begin with, we have a good illustration of how it is sometimes good to doubt. But note this: we doubt one testimony precisely because we don't doubt another. This means that the wise person apportions doubt to the evidence or, if you prefer, to the context. It is good to doubt the testimony of a nine year old that seems to conflict personal experience and the testimony of a trusted authority (National Geographic). But it is only good to doubt the nine year old because you believe your experience and the testimony of the trusted authority.
Thus it is simply wrong to say "Doubt is good." Sometimes it is good, and sometimes not.
As you can guess, the same points apply to skepticism. It is false to say "Skepticism is a virtue". Rather, proper or reasonable belief is a virtue, and as Anthony Kenny has pointed out, reasonable belief entails finding that golden mean between excessive credulity and excessive skepticism.
This is important because it demonstrates the fact that self-described skeptics like Michael Shermer who like to pride themselves as being eminently reasonable, often only get half the equation of reason: the side of doubt/skepticism. But as I said recently (and will say again), equating reason with skepticism is like rowing on only one side of the boat. Do that for too long and you end up going in circles.