Short quotes and comments found wherever.

Friedman explains this quote by saying the reality we inhabit is "too complex" to analyze directly. We have to "simplify the world down to an image of it". Friedman uses this to argue that Adam Smith and others absorbed the "religious worldview" of their time as their "simplified image" of how the world works.

In Einstein’s 1918 speech Principles of Research, he continues: "This is what the painter does, and the poet, the speculative philosopher, the natural scientist, each in his own way. Into this image and its formation he places the center of gravity of his emotional life, in order to attain the peace and serenity that he cannot find within the narrow confines of swirling personal experience."

We need models of how the world works to interpret it.

This aphorism is generally credited to George E. Box. I first heard it in an earth dams course from Dr. Jonathan Fannin. It is obviously applicable to engineering models, but also broadly relevant. For example, there is a way that language is a model. The words we use are representations (or models) of some concept we want to share; they often don't perfectly match the idea, but we use them to our great benefit.

To bridge 1 and 3, if it matters, it can be measured. A key driver of much of the most recent technological progress (AI as one example), and a class of problems I find interesting, are domains where solutions can be found by iterating towards well-defined, measurable objective functions. In Hubbard's framing, useful metrics can be found for any problem, and anything useful can be measured. Better measurements can help us make progress towards many problems. There are many clear limits to this framework, but it strikes me as a useful idea to keep in mind.

The quote continues, "And, just because it's a concept, doesn't mean it's less real. Is three less real to us? Where is three? Show me the platonic idea of three in nature. No, it's a concept; and yet, it feels as real and we honor it and we use it. Free will is a concept that emerges in this deterministic system, so let's honor it and use it"

Thinking about the number three, or free will, as concepts that are useful and "real" without requiring a Platonic ideal in nature is a useful framing.