The contextuality of scientific truth
What does it mean to say that a statement is true? Is truth absolute or relative?
In philosophy, there are two opposing views about truth. The correspondence theory of truth asserts that the truth or falsity of a statement is determined solely by whether it accurately describes reality. This assumes that there is an objective reality and that it might be described faithfully. The coherence theory of truth on the other hand asserts that the truth or falsity of a statement is contextually dependent on other statements. Many confusing statements about time are based on the correspondence theory of truth.
Before we can discuss our main principle, contextual completeness, outlined below, we need to distinguish three forms of truth:
An absolute truth is a proposition asserted to be true under all circumstances or contexts. An example is ‘time is continuous’. Because such statements are by definition metaphysical, physicists should avoid absolute truths as a matter of principle.
Isaac Newton was aware of the dangers of absolute truths, particularly about space and time. In his book The Principia Newton defined his concept of Absolute Time as if it were an absolute truth, but immediately qualified it with a statement about his concept of relative time, which he defined in terms of observation of motion [Newton, 1687]. As in so many matters, Newton knew what he was doing. We discuss Absolute Time in Chapter 14.