It is common, even among the laity, the doubt about the reality of time. We think it is possible that time is an illusion and that the perception of his passage is just awareness of something other than time. There are a number of arguments made by philosophers, both to defend and to attack the intuition that time is real. One of them, and perhaps the best known, is the argument of McTaggart, which tries to establish some condition for the existence of time and that time, thought through that condition and applied to reality, leads to a contradiction, which makes him conclude that time can not exist, and therefore does not exist. What I intend in this article is to present the argument of McTaggart along with some original and non-original objections, and try to show that if we accept the Prior’s approach of the flow of time, the cogency of the argument of McTaggart is lost.