Sir Isaiah Berlin, in his 1958 essay and inaugural lecture, "Two Concepts of Liberty," expands on the ideals of liberty that were synthesized and inculcated by earlier political philosophers. The essay initiates and details an outline of an idealized liberty with two distinct branches: positive and negative. Although the essay is a bit controversial, producing such detractors as Charles Taylor, this seminal piece has staying power and can only be enhanced, not nullified