The third-rate mind is only happy when it is thinking with the majority. The second-rate mind is only happy when it is thinking with the minority. The first-rate mind is only happy when it is thinking.A. A. Milne
In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual.Galileo Galilei
Everyone thinks but some are better thinkers than others. Good thinking is more likely to lead to right conclusions, right beliefs. Good thinking can change your mind, change your beliefs. None of us are lucky enough to have been born or raised with all of the right answers. Good thinking makes it possible to recognise where our beliefs are wrong so we can improve them. Constantly improving our wrong beliefs leads us ever closer to right beliefs.
Right beliefs are beliefs that are most consistent with what we can observe. In ancient times, the Earth was believed to be flat because to a casual observer, it appeared flat. But to a more astute observer, it appeared curved: ships descended lower into the horizon as they got farther away from view. To an even more astute observer, measuring the angle of the shadow cast by vertical poles at the same time of day but placed miles apart allowed one to calculate the curvature of the Earth and therefore deduce that it's a sphere. Accepting that the Earth is round required good thinking on the part of our ancient ancestors. Now that we can see the Earth from space, we can confirm that the good thinking of our ancestors led to right beliefs.