Arguing on the Internet: Another Naive Atheist

I just read Ricky Gervais' op-ed in the Wall Street Journal, Why I'm an Atheist. It's well written, and it's nice in a lot of ways. I couldn't help agreeing with a lot of things he says. Gervais doesn't have the mesoraphobia and political ambitions of Dawkins' New Atheist crew. However, when Gervais starts talking about science and religion, he shows some naivete, in my arrogant opinion. So here's a platonic dialogue, where Gervais' lines are taken from the op-ed itself.

Ricky: Science seeks the truth. And it does not discriminate. For better or worse it finds things out.
Daniel: What do you mean, "science doesn't discriminate"? Do you mean that science isn't biased? Come on. Lots of scientists are biased. The scientific community has no shortage of biases.
Ricky: Science is humble.
Daniel: Oh, come on. I'm sure the scientific community could be more arrogant than it is, and of course many scientists are humble, but on the whole, the scientific community is not humble.
Ricky: It knows what it knows and it knows what it doesn’t know.
Daniel: Does it? Did 18th century science know what it didn't know? Scientists who think they know what they don't know are arrogant indeed.
Ricky: Whatever you “believe,” this is not as effective as medicine.
Daniel: What is that supposed to mean? Effective at what? According to statistics, religion seems to be pretty "effective" at making people happy. Religion may not be as effective at medicine in curing pneumonia, but neither is vector calculus. So what?
Ricky: From what I’ve heard the very definition [of God] is a logical impossibility in this known universe.
Daniel: Who told you that? That's not science. I think you've been reading too much Dawkins.
Ricky: You know, you're right. I should take the paragraph about science out of my WSJ op-ed.
Daniel: Wait a minute, you're only supposed to say things in this dialogue that you actually said in the op-ed.
Ricky: Why are you complaining to me? You're the one writing this blog!