"Old scientific sign-posts were done away with, and Erasmus was one of the pioneers who installed a new one pointing to Evolution. Two generations later it was his grandson Charles's turn to express new ideas, built on new knowledge. It became his turn to correct old sign-posts, and his grandfather's was one of those he repainted. On the newer sign-post was again the word Evolution, but he added Natural Selection as a pointer how to get there. More significant than a direction to any final goal, was the clear guidance on how to read the map."