what are the prejudices of the author

Although the question is a little vague, the most important presupposition (prejudice) that underlines Hobbes' entire work is that of his thoroughgoing materialism. Hobbes is convinced that human beings can be and ought to be explained in entirely physical terms--rejecting the classic dualism of Plato, Descartes, etc. Because of this conviction, he is extremely wary of human beings left to their carnal, "natural" selves. This is where the Leviathan State must assert itself.