Critical Theorizing

I found the following posted on Greg Mankiw’s blog under the heading “An Epistemological Digression.” The passage comes from Robert Pirsig's Zen and the Art of Motorcycle Maintenance.
After a while he says, "Do you believe in ghosts?"
"No," I say.
"Why not?"
"Because they are un-sci-en-ti-fic."
The way I say this makes John smile. "They contain no matter," I continue, "and have no energy and therefore, according to the laws of science, do not exist except in people’s minds."
The whiskey, the fatigue and the wind in the trees start mixing in my mind. "Of course," I add, "the laws of science contain no matter and have no energy either and therefore do not exist except in people’s minds. It’s best to be completely scientific about the whole thing and refuse to believe in either ghosts or the laws of science. That way you’re safe. That doesn’t leave you very much to believe in, but that’s scientific too."
Science only tells us what exists, right? And only things that have energy exist. According to this somewhat silly argument, law in general can’t really exist except in our imagination, (and I mean ‘imagination’ in a very sophisticated way). And because laws are not real, that means that the scientific conclusion we arrive at using those laws are unsound, and we can’t prove much of anything scientifically. We must have conjectured theory to logically guide our scientific methods. This is where my methods class and my theory class meet. Even in 300, we talk about the importance for content validity in the context of setting up experiments and hypotheses. Really, what can we know except what we expect that we will come to know.
There is no free knowledge. Everything we learn we first must anticipate through theorization. And I’m talking about those things that we understand. Sure we can discover things blindly, but how much do we comprehend them? All epistemology starts with ‘what if?’ What if the earth was round? What would happen? There’s only one way to find out. Well, two ways. Launch a satellite with a camera on it into space to take a picture of the planet, or sail around it. Seeing how King Ferdinand didn’t have the means to take a picture of the earth, he settled for the latter and sent Columbus on the ocean blue. But it started with a theory.
Would alternative possibilities also describe the phenomenon? It seems that we respect and revere those who ask this question more than any other kind of person. Columbus is one example. Another is Benjamin Franklin. He essentially thought that something other than the sin a member of a certain household committed, thus bringing the wrath of God upon that house in the form of a lightning-started fire, could cause the house to be struck by lightning. The outcome is the same, that is a burning house, but the cause could be different. Through this process, Franklin developed the building-saving lightning rod to redirect the lightning’s energy away from the house. The church, it seems, would now have to look for some other deterrent from sin than a lit-up house.
So, what are some alternatives to present posits? And I’m no natural scientist, so I’ll have to stick with social science. What’s so bad about gay marriage? Why is “socialized health care” a bad word? What would a minimum wage increase do? Is complete laissez-faire really going to bring prosperity to everyone, even the poor? Are we actually capable of even knowing these things?