We seem to have evolved two antithetical approaches to dealing with this: do as little as possible because we really don't know what we're doing, or alternatively, we must adopt an activist approach and seize control of the chaos and make changes to solve problems or institute solutions while they are still amenable to intervention and before they have become institutionalized and developed a constituency that will resist change and improvement. We call these the conservative and liberal approaches, respectively.

This premise, of course, assumes that the "activist" also knows what they're doing when making all these changes. Is this usually the case? If, in fact, they don't know what they're doing either, the balance between minimal intervention and making all kinds of changes gets a little more complicated.

(As an example, does the current economic activity in Washington look like the actions of brilliant individuals more farsighted than all the rest of us, or does it look like people pulling levers and pushing buttons at random, hoping the red lights on the machine turn green?)

Which of these approaches is really better? How much of liberalism (as defined in your premise) relies on the assumption that someone in a D.C. office building is by definition much wiser than someone in an office building in Silicon Valley? Or someone working in a factory, or farming his land?

Is one political leader automatically going to make better decisions for thousands of people than those thousands of individuals making decisions based on their own needs and thinking?

We can pull away from the philosophy issues, pull back from objectivity, from "right" and "wrong," and just look only at the results.

When you look at hundreds of nations, and graph prosperity and freedom against the level of state control of the economic system, how does it look?

Something like this:

There are outliers, but not many.

There are similar charts like this from other sources. Two sources of information on economic freedom ratings are the Heritage Foundation and the Fraser Institute.

Are we near a tipping point for centralized control over our economy? Probably not. But as government control increases, as it likely will in the near future, by definition we are moving toward that point.

We can't keep going in that direction forever, and it is hard to find liberals who will put a stake in the ground and say "this far for state control of the economy, and no farther." There seems to be no upper limit.

Where is your stopping point? Anyone's here? Where does the stake go into the ground? "State ownership of the means of production" is a red herring. It doesn't matter who "owns" a corporation if it's controlled and regulated by the State at every conceivable level of activity.

BTW, your naval architect friend may not have had an objective math calculation for every design decision, but neither were his decisions arbitrary. "Subjective" is kind of a loose term to apply to decisions made based on years of experience, hundreds of precedents, what works, and what doesn't.