Abstract
‘Lessons and meanings’ discusses the fundamental philosophical debate between positivism, where science's role is seen as the reconciliation of observational data, and realism, where science's role is seen to be to discover what the physical world is really like. Pragmatism offers a halfway house — the philosophical position that acknowledges the technological fact that physics enables us to get things done, but that does not go as far as a realist position in thinking that we know what the world is actually like. Reality; reasonableness; the metaphysical criteria of scope, economy, and elegance; holism; and the role of the observer are all discussed. Finally, there is a warning against quantum hype.