Charles Darwin saw through the mere appearance of things and would not settle for biased or fantastic explanations of the world. He was a prudent and very studious person, and like any Aquarius-Capricorn individual able to work towards a cause or belief, putting the self and its petty needs on the back burner for as long as it takes. Aquarius, idealistic and humanitarian, will forever seek the unifying cause, the collective truth, the beneficial and enlightening solution for society. Capricorn, while less concerned with society, has a tendency to neglect personal issues just to get the job done. The goat is perhaps even better yet at detaching themselves in the quest for a remote objective. These energies together create a desire and drive for "truth" and learning throughout life.
We can probably rule out the possibility that Darwin was a supporter of horoscopes and astrology. Unknowingly, however, he spoke of his own Sun-Moon combination with great insight: "I am turned into a sort of machine for observing facts and grinding out conclusions." The poor man must also have had very little spare time, it seems: "A man who dares to waste one hour of time has not discovered the value of life."
Darwin was dedicated to his revolutionary ideas on natural selection and the evolution of the species, yet torn between his scientific convictions and the traditional views dictated by his inner Moon in Capricorn. Even at the height of his research on evolution, making the idea of a moral and purposeful God a lot harder to comprehend, he was not able to abandon the idea of God as an ultimate lawgiver. Furthermore, the Sun in Aquarius as in Darwin's horoscope is usually liberal and open to different world-views, which may have added to the hesitation in deeming religion unworthy of consideration.