Mr. Darwin was a very careful man. Like a good scientist/engineer, he would check and double-check his data to prove his hypotheses. The hypotheses of evolution was and still is a difficult subject to prove, as it would like thousands and millions of years for evolution to take place. His painstaking work on barnacles and other species showed that he assumed a lot of pride in his work.
His peculiarity in dealing with deaths of loved ones and respected colleagues by not attending funeral services showed his deeply seated belief that our lives end at the time of death. There was no afterlife or heaven and hell to him. This ran into conflict with his religious wife, who gave births 10 children, 3 of those died at young age. Through his love for this children, he seemed to express deep dissonance that the afterlife doesn’t exist.
His rush to publish the “Origin of Species” as an abstract was prodded by another colleague, who had similarly reached the same conclusion about evolution/transmutation, and etc. This had resulted in a writing more concise and easy to understand than his other writing. (I haven’t read the “Origin of Species” yet. It’s on my to-do list).
Fortunately, Darwin had a rich father, who passed on to him lots of wealth and assets. This allowed him to concentrate on his research/field work. Without the wealth, Darwin may need to resort to academia that would probably put him in the same group as any others. His uniqueness may have been a byproduct of his financial independence.
For a man living in that era, it took a lot of courage to publish his work and his belief. Darwin may have been reluctant to go against the grain of the largely religious society, but he finally gave in to speak his mind, risking ridicule of others. How’s that different from a modern hero?