Metaphysical Reality
Bacon's essays begin with a treatment of the metaphysical realm within which human experience occurs. This reality is dramatized and described as a bustling and complex community. He sees that human experience is easily taken for granted, and the experience has a number of limiting factors. For instance, he notices that humans experience life within the emotional demands of their need for community and knowledge. This means that wrong or limited ideas can be perpetuated for millennia because no one really wants to be right when everyone else is being wrong; it is not a pleasant experience of reality. The metaphysic that Bacon describes is one where, through careful examination, new knowledge could easily (and sometimes not so easily) be attained, but first the human communities would have to impose methods for overcoming the limits of perception.
The Cave
This imagery is a direct allusion to an allegory from Plato's Republic, but Bacon uses the shape of that allegory to another effect. The concrete imagery is that human perception can be seen through the lens of a person trapped in a cave; they have to depart the community to attain a higher understanding of reality. The abstract application for this imagery is that scientists have to abandon the comfort of presuppositions and biases to become objective, which is like departing the cave the community resides in. This process is described as intimidating and unpleasant.
Dark and Light
Bacon's essays address a myriad of civil and moral topics, and to illustrate his points he often uses imagery of dark and light. When praising something – like virtue, for example – Bacon relies on imagery of light, brightness, and divine appearance. By contrast, topics like envy and superstition are replete with dark imagery like bats, illness, and storms.
Trees and Divisions of Labor
Bacon sees that science is not just one process, but rather, he suspects that there will be schools of scientific inquiry that arise from the specific applications of the scientific method to various intentions. Each of these schools is likened to a different "branch" on the tree of knowledge. For instance, the application of science to the success of human health is called medicine. The application of science to the reality of the world is called physics, and the application of science to productivity is called technology. These various branches are still part of the scientific body, but they have their own particular functions in human experience.
