This week will see Chris Eddy talking on this topic. He says:
The ultimate question is not about what is true, but rather about what is good: it is always a practical question, – “How ought we to live?” (Socrates) “What must I do to be saved?” ( Acts) “What is to be done?” (Lenin). Truth matters only as it helps us decide what to do or refrain from doing.
Truth is a relation not between words and things, but between interlocutors: i.e., between speakers who, in making claims, exercise authority and thereby incur the responsibility to justify them to each other. If I say that a particular statement is “true”, I am implicitly asserting that we ought not to contradict it nor, when acting, to disregard it, and thereby making myself responsible for justifying it to you if called on to do so. To justify a truth-claim to you, e.g., about the Higgs boson, the battle of Waterloo or the existence of God, I must give you the kinds of reason for assenting to it that you might offer as reasons for my assenting to truth-claims made by yourself: the kinds of reason which are available to both of us and in that sense objective and non-arbitrary, but also acceptable to both of us as the right kind of reason for assenting to that truth-claim.
If you accept my reasons for my truth-claim, then that claim becomes something we can both appeal to as a “fact”. Facts do not exist until they are stated and agreed. Facts are derived from experience, but experience is not a given. Experience is what we are conscious of, but we are conscious only of what we are paying attention to (a fact which stage-magicians exploit), and this is where language has a foundational role in experience. The attention of dumb animals is at the mercy of events, drawn hither and thither by chance phenomena inside and outside their bodies, and they cannot resist being distracted by each new salient phenomenon; but language enables us to resist distraction, i.e., not merely react to particular phenomena, but focus our attention on them and construct them as objects of conscious experience.
Any object or event can be seen as in some respect like or unlike every other, and we construct our experience, using language to focus attention on particular patterns of likeness and difference, i.e., ways of categorizing experience. As we attend and collectively react to those patterns, we come to see them differently, new patterns are proposed and recognised, and so there is change in our experience, in the facts and therefore in what we accept as true. Ptolemy’s Solar System yields to that of Copernicus, Newton’s gravity to Einstein’s.
But our commitments as speakers require us to ensure that every statement we propose as a fact is consistent with, or corresponds to, every other such statement, so that any change in what we recognise as true can be very costly in terms of the intellectual effort required to readjust the whole existing system to the demands of the newly constructed fact, which helps to explain why people are generally reluctant to change their minds about the facts. The Correspondence Criterion for Truth, – that a statement cannot count as true unless it corresponds to the facts, – turns out to be simply another way of stating the Coherence Criterion, – that no statement can count as true for us if it is inconsistent with any other statement we accept as true.”