At last gleams of light have come, & I am almost convinced (quite contrary to opinion I started with) that species are not (it is like confessing a murder) immutable.

Charles Darwin, writing to his closest friend, botanist Joseph Hooker, detailing his feelings as the Theory of Natural Selection took shape.

This is an excerpt from a newly released collection of  over 1,000 letters from Charles Darwin to Hooker throughout the course of his life. They provide an unprecedented view of Darwin’s struggles and emotions, enriching the humanity of this great scientist.

Tour the letters at Cambridge University’s Darwin Correspondence Project, and read more at BBC News.

(via jtotheizzoe)