When we usually think how advances in a field of knowledge are made, typically the first thing our mind goes to is new discoveries – e.g., in archaeology or astronomy, or maybe a fresh reinterpretation of old data. How many other ways could we list? James Beattie gives four more:
Yet he who makes these sciences the study of his life, may perhaps collect particulars concerning their evidence, which though known to a few, are unknown to many; may set some principles in a more striking light than that in which they have been formerly viewed; may devise methods of confuting new errors, and exposing new paradoxes; and may hit upon a more popular way of displaying what has hitherto been exhibited in too dark and mysterious a form.
This is from the introduction to An Essay on the Nature and Immutability of Truth. In context, Beattie is only talking about the areas of logic and morals, and even there he is not trying to be exhaustive. Yet many of these could also apply to the natural sciences and humanities. His list has further value because he gives examples which we would usually ignore because they seem like insignificant actions. But they are in fact important. The first actually has a lot to do with how modern scientists do their research (it’s not all glamorous discovery!). The fourth can be seen in the development of calculus, which most people see as solely the product of Newton’s genius, but in reality it was not set on firm principles until later. The other two seem more to have to do with spreading, popularizing, and defending ideas, which are also significant if we take ‘advance’ to involve the general acceptance of proven hypotheses.