The whole chasm of nature, from a plant to a man, is filled up with divers kinds of creatures, rising one over another, by such a gentle and easy ascent, that the little transitions and deviations from one species to another, are almost insensible.
Existence is a blessing to those beings only which are endowed with perception, and is in a manner thrown away upon dead matter, any further than it is subservient to beings which are conscious of their existence.