Here's an interview he gave with The Humanist: Thinking Like a Scientist.
The Humanist: How do you define critical thinking?This is important stuff. I think of "science" as a way of knowing but it can also be thought of as a way of thinking. It's intimately associated with critical thinking.
Rush Holt: Let me define instead what I like to call “thinking like a scientist.” It’s asking questions that can be answered based on evidence; it’s expressing questions in a way that allows someone to check your work. If you don’t have both of those elements, it’s too easy to fool yourself or to get lazy in your thinking. I wouldn’t say that critical thinking is hard thinking, because I don’t want to discourage people from doing it, but like anything else, it’s easier if you practice.
Third graders, for example, are often very good at thinking like scientists. Like scientists, they know that if you ask how something works, what something means, or how something happens, you should do it in a way that allows for more than just pure thinking. There should be some evidence, something empirical. You should form your question so that it allows someone else to ask that same question and observe the evidence to see if they get the same answer as you do. And that’s the essential part of critical thinking. If you say, “I’ve been thinking about this deeply and, by golly, now I understand it,” but then you try to explain it to someone else and can’t, then you probably don’t understand it … or it’s not very reliable knowledge.
I keep trying to get science taught in a way that, even if you can’t remember a single Latin term or are a klutz at solving equations, you’ve learned how to frame questions and sift evidence. I talk about verification but another way of putting it is: be ready for the cross-examination. Prepare to explain yourself.
The Humanist: How valuable is critical thinking to everyday life?
Holt: It’s invaluable, whether you’re making a consumer decision like which laundry detergent to buy or whether you’re trying to decide what career you want to pursue. There are ways to ask yourself both what you’re trying to accomplish and how to measure whether you’ve accomplished it. If you’re able to express it that way, then you’re thinking critically.
This is important on every level, not just on a personal level, not just in regards to consumer decisions or life choices. I think it’s quite likely we wouldn’t have invaded Iraq if more people in the CIA or in Congress had been thinking critically and asking, “What’s the evidence? You say Saddam Hussein is doing things that will hurt our national interests. Now tell me exactly: what is he doing? Does he have chemical weapons, nuclear weapons? Where’s the evidence?” Of course, there wasn’t any.
In this sense, "science" is not confined to the so-called "natural sciences" but it can be applied to everything that requires a search for reliable truth. Everybody should be thinking like a scientist and that includes politicians and philosophers. In my experience, there is no other way of knowing that has a proven track record.
[Hat Tip: RichardDawkins.net]