IntroductionTime is definitely among the most familiar concepts that we have come across, yet it is one of the least understood. We need it in everyday life; it tells us when to wake up, eat, go to work, exercise and sleep. We simply cannot live without it, yet we are still struggling to understand what exactly it is. This report will look at This report aims to: ABCDefining TimeWhen asked what the definition of time is, a normal person would probably respond with something along the lines of ‘time is whatever clocks measure’. But that seems to be hopelessly operational, and leads to further questions: what, then, is a clock? It is no help to be told that ‘clocks are whatever measure time’; we want some way to break into the definitional circle. Without clocks, time would still exist but without time, clocks would not exist. So, perhaps it is better to think of clocks as measuring time, and come up with a way of understanding time independent of clocks. Upon emailing Adam Caulton (Lecturer and Tutor in Philosophy, Balliol College, Oxford), he presented a definition of time in terms of events. To define an event first, he said “what I mean by ‘event’ is … something that happens within a fairly small spatial region and over a fairly small period of time.” From this, we can infer that “a fairly small spatial region” and a “fairly small period of time” is in relation to the whole universe and the whole timeline (since the word ‘small’ is relative). So, according to this, a click of your fingers is an event, as is the collision between two objects, or an explosion.He continued on with “but we can imagine events that happen within increasingly smaller regions of space and over increasingly small periods of time. The limiting case is a pointlike thing: it is located in space and time, but has no spatial or temporal extension. Events are real — this is undeniable. Perhaps there are pointlike events — our best theories seem to suggest that.” This raises a big question: how are the events arranged? How are they ordered? According to Einstein’s theories of relativity, they are ordered in a four-dimensional continuum. Time is one aspect of this ordering. However, this notion of time is much thinner than the everyday notion. For example, it does not necessarily have a direction and it does not necessarily “flow” (this will be discussed in detail later in the report).Time Doesn’t FlowThe A-series and B-seriesWhat, then, is the past, present and future? When it comes to time, philosophers are broadly divided in two groups according to their beliefs: one group believes what is known as the A Theory, and the other group follows the B Theory. A Theorists believe that time can be divided into the past, present and future – and they are all temporal properties and real distinctions one can make. For example, World War 2 has the property of ‘pastness’. Time passes as it flows from the future, into the present, then into the past. B Theorists believe that all times are equal and that there is no such thing as the ‘present’, ‘past’ and ‘future’. The ‘present’ is just the name we give to the bit of time that we are in, but all times exist equally. John McTaggart Ellis McTaggart, British metaphysician in the 19th-20th century, rejected the B-series because he thought it ruled out the possibility of change. “The B series by itself is not sufficient for time, since time involves change.” Published in Mind: A Quarterly Review of Psychology and Philosophy 17 (1908): 456-473 (John McTaggart Ellis McTaggart). McTaggart thought that change is of the essence of time and time necessarily involved change. The events that form a B-series must also form an A-series in order to count as being in time, i.e. they must pass from future to present, and from present to past, in order to change. He thought that if time exists, it has to be like the A Theory. But, he also rejected the A-series because of something now known as ‘McTaggart’s Paradox’. It is true that the A properties are mutually exclusive; nothing can have pastness, presentness and futurity all at once – that is a contradiction. The obvious response to this would be that nothing has all three properties at the same time; it starts with having futurity, then presentness, and finally pastness. But McTaggart goes one step beyond: if an event is in the future, then it will be in the past. This means it has second order temporal properties: it has present futurity (currently in the future), and future pastness (will be in the past). When it is in the past it will have past futurity (used to be in the future). But again, we get a contradiction. No event can have both future pastness and past futurity – that would mean it is and is not in the future, which does not make sense. So again we say it does not have these properties at the same time, it currently has future pastness and then it will have past futurity, which is to say it has third order temporal properties. But again, some of the third order temporal properties are contradictory so we have to go to fourth order and fifth order, and so on, creating an infinite loop. No matter how many levels you pursue them to, the contradictions of McTaggart’s Paradox always come back. For this reason, McTaggart rejected the A-series and therefore concluded that time does not flow or exist if it does not follow the A or B Theory. McTaggart’s beliefs are the beginning of the modern metaphysics of time, although McTaggart’s Paradox is not thought of being a great argument anymore because of how much theories have developed.