Absolute truth is something that is true at all times and in all places. It is something that is always true no matter what the circumstances. It is a fact that cannot be changed. For example, there are no round squares. There are also no square circles. The angles of a triangle add up to 180 degrees. These are all true by definition. Very similar are the propositions of Euclid, because they are proved once the axioms are accepted. One way or another, these are all truths because they are logically true. Absolute truths are discovered, not invented. They exist in all cultures.