In one of my entries below, I wrote something to the effect that "not all laypersons are 'independent thinkers'".
What I mean there is that someone who is called an "independent thinker" is someone who, contrary to evidence, facts and logic of first principles, persists in thinking that the planet Earth is flat, that the universe is only about 6,000 years old and that the fossil evidence is the work of the Devil, that human ingenuity and creativity on its own is incapable of creating a Mona Lisa, Angor Wat, the great Pyramids, the physical theories of Newton and Einstein without the beneficence of extra-terrestrial aliens.
A critical thinker, by contrast, is someone who seeks answers and solutions from first principles and accepts or rejects evidence using reasoning (no matter how simple or convoluted the arguments). The other difference between "independent" and "critical" thinking is that the former is a view that is static and takes on faith what the "authorities" say on the hows and whys of the world, and whose worldview tends to be dogmatic and rigid; the latter's view and knowledge is participatory and dynamic but whose dynamicism is evolutionary and organic and unwavering in a way similar to the Pauline doctrine:
"When I was a child, I talked like a child, I thought like a child, I reasoned like a child. When I became a man, I put the ways of childhood behind me. For now we see only a reflection as in a mirror; then we shall see face to face. Now I know in part; then I shall know fully, even as I am fully known. And now these three remain: faith, hope and love." (1 Corinthians 13)