Philosophy is first of all a way of thinking rather than a fixed body of knowledge. Specifically, philosophy is the practice of thinking about what, why and how we think. This “thinking about thinking” involves asking questions about what we know and believe, about what we think is true and false, right and wrong, just and unjust, real and unreal, valuable and valueless, the relationship between language and reality, the nature of consciousness, freedom, justice, truth, happiness, goodness and a host of other topics. The purpose of this philosophical questioning is both to clarify our own thinking and to determine whether we have good reasons for thinking as we do. The reasons for our beliefs, and the validity of those reasons, have a direct impact on the reliability of those beliefs. And once they are presented, these reasons make themselves available for evaluation by others. Philosophy therefore does not offer comfortable certainties, but an intellectual adventure in which everything is up for questioning and reassessment. At the same time, philosophy provides us with the means for dealing with – rather than overcoming or denying – radical uncertainty. The value of philosophy is that it teaches us to recognise the limits of what we know, without succumbing to despair in the face of what we do not know.