(Still swamped, but have a couple minutes, so – )
Michael Flynn mentions from time to time Einstein’s quip to Heisenberg: “Theory determines what can be observed.”
Let’s pair that up with an observation made by Aristotle: It is the mark of an educated mind to be able to entertain a thought without accepting it.
So: the exercise of an educated mind is that of holding a thought – say, a theory, which is certainly a kind of thought – and seeing the world as filtered or selected for by that theory WITHOUT necessarily accepting it.
Conversely, an uneducated mind cannot hold a thought without believing it. Attempts to see the world through someone else’s eyes are filtered by accepted theory FIRST, THEN only those items which are in harmony with the accepted theory are allowed through to be considered. Thus, an uneducated materialist will accuse a realist of the Thomistic or Aristotelian school of speaking nonsense when final causes are brought up, because he is unable to even see them well enough to entertain them, insofar as they cannot exist under his theory.
So, how does one get an educated mind? First, no human mind is ever perfectly educated, so it will always be a matter of degree. Also, I suppose no mind is ever completely uneducated, although in many, education appears only as an evanescent quantity, usually as a result of years of training.
The classical way is the best way: by learning what many great thinkers have thought, by wrestling with their ideas , by defending and attacking those ideas, one gets ‘educated’ in precisely the sense of the quote from Aristotle above: one learns how to hold an idea without accepting it.