Intelligence is: (a) the most complex phenomenon in the Universe; or (b) a profoundly simple process. The answer, of course, is (c) both of the above. It's another one of those great dualities that make life interesting.
Any man who is intelligent must, on considering that health is of the utmost value to human beings, have the personal understanding necessary to help himself in diseases, and be able to understand and to judge what physicians say and what they administer to his body, being versed in each of these matters to a degree reasonable for a layman.
As we gradually learn to harness the optimal computing capacity of matter, our intelligence will spread through the universe at (or exceeding) the speed of light, eventually leading to a sublime, universe wide awakening.