Jacob Bronowski's metaphor addresses the limits of human knowledge and understanding. It was an early inspiration for the Homo discens project. Bronowski (1973: 353) declares that twentieth century physics has proven that “an exact picture of the material world” is unattainable. He compares science to “the method of the artist”:

We are aware that these pictures do not so much fix the face as explore it; that the artist is tracing the detail almost as if by touch; and that each line that is added strengthens the picture but never makes it final.