Time plays a fundamental role in everyday life as well as in most sciences and historical disciplines. Science as a systematic study into the natural, social and human spheres of life examines all sorts of processes that take place in time. But, apparently, science has very little to say about the way we think about time and the nature of time itself. This is because we cannot define time in terms of any other concept; on the contrary, we use it in the specification of other concepts. Time seems to be a fundamental concept which we have to accept as a precondition for our understanding of our own life and the whole universe around us. This does not imply, however, that time itself cannot be an object of inquiry, or that it can only be grasped intuitively. Even if we cannot provide a formal definition of time, something instructive and important about time can always be said concerning how it is related to other fundamental concepts like space, event, thing, causation, free will and human experience.