William Henry Fox Talbot was the father of the calotype and fore-runner of the negative-positive process. He realised that you needed skills for the camera lucida, as you needed to be able to draw. Talbot wanted something that could be easily reproduced and thus created the calotype.

Camera Lucida 

The Camera Lucida was an optical device used for drawing. The artist sees both the scene they want to draw and the drawing surface (like a double exposure). 

Calotype

A photographic process introduced in 1841, by Talbot, which used paper coated with silver iodine. Calotype comes from the Greek καλός (kalos), "beautiful", and τύπος (tupos), "impression".

Pencil of Nature 

Some historians say 'Pencil of Nature' - written by William Henry Fox Talbot - was one of the first books illustrated with photographs.

"plates of present world impressed by the agency of light alone.... They are the sun pictures themselves..."

The above quote implies that Talbot thought photography was objective and humans couldn't interfere with it. Talbot believed that photos could be seen as evidence in court as it shows that certain objects exist. He showed this with Articles of China, 1844. His words had a huge consequence as photographs are now legally excepted as truth. For example, an ID photograph shows how a photograph has more legal power than you.