| A collection of nonfiction essays written by Ayn Rand. It explicitly delineates the philosophy set forth by Rand in her earlier fiction work. It gives a comprehensive answer to the question set forth in the title.
According to Rand, reason is not a mere characteristic of human beings, it is their most important means of survival. Rand looks at the power that philosophy has in everyone's life and critically examines the philosophical trends that have existed throughout history until today.
"You have no choice about the necessity to integrate your observations, your experiences, your knowledge into abstract ideas, i.e., into principles. Your only choice is whether they represent your conscious, rational convictions - or a grab-bag of notions snatched at random, whose sources, validity, context and consequences you do not know, notions which, more often that not, you would drop like a hot potato if you knew." (5)
Rand stresses the idea that knowledge is not intrinsic or subjective; it is objective, and all individuals must use their rational faculty to acquire it. Consciousness is not a passive state, it is an active process.
Philosophic systems and their influences on various academic fields are examined in the work. Particularly powerful is her analysis of B.F. Skinner's work Beyond Freedom and Dignity:
"The significance of B.F. Skinner's book lies in its eloquent demonstration of the results of philosophical collapse and governmental power: when the intellectual default of the victims permits the dead hand of the government to get a stranglehold on the field of ideas, a nation will necessarily be pushed beyond freedom and dignity." (161)
This work of Ayn Rand's illuminates the extensive influence of philosophy in all areas of life. It displays the nature of today's trends, and shows how the individual can work to change them. | 
