Philosophy differs from many intellectual disciplines in that it is fundamentally a normative discipline. Unlike those disciplines whose primary aim is to describe various phenomena, philosophy aims to evaluate our views, attitudes, and behavior. At the societal level, philosophy seeks to identify and critically evaluate the cultural assumptions and dogmas of the day, exposing indefensible assumptions as mere prejudice. At the personal level, philosophy challenges us as individuals to assess whether our own beliefs, attitudes, and practices are justifiable, with an eye toward abandoning or revising those beliefs and practices found to be unjustifiable.
As a result, philosophical inquiry often proves profoundly valuable both for society and for the individual. Principal among philosophy's contributions to society is its power to reform: Most of the great social reform movements of the modern era have grown out of philosophical challenges to the status quo. At the personal level, philosophical self-examination helps us to live authentic, meaningful lives. By subjecting our beliefs, attitudes, and practices to critical scrutiny, we learn what our most deeply held values are—an essential first step toward acting in accordance with those values. When philosophy helps us to live our lives in conformity with our most deeply held values, it becomes a transformative experience.
(Mylan Engel Jr and Kathie Jenni, The Philosophy of Animal Rights: A Brief Introduction for Students and Teachers [New York: Lantern Books, 2010], 7 [italics in original])
Note from KBJ: I reject this conception of philosophy. To quote Peter Winch, "philosophy can no more show a man what he should attach importance to than geometry can show a man where he should stand." The purpose of philosophy is to clarify concepts. This includes showing people the implications of what they already believe.