Charity and Skepticism
"True freedom comes only to a lucid mind unbound by conventional wisdom and suspicious of received opinions."
That's Joseph Epstein, writing about Santayana in Essays in Biography. It's a great aphorism. It reminds of GKC's observation that only dead things swim with the current, but that live things kicks against it.
I realized a few years ago that I'm pretty impressionable. It's a nice trait in some ways, but overall, it's the trait of a weak mind and one that instills a level of intellectual servitude. I've slowly replaced it with a sense of skepticism, which I far prefer. Even though the skeptic is often a bastard, if you strive to combine it with love, you can curb its richard-ness tendency.
Then again, any trait combined with charity curbs its blunt edges.