I think the point is that, for a new theory to become more favored than the current leading theory, the new theory must be consistent with at least as much scientific evidence as the leading theory. From there, the value of predictions is that they give a path for strengthening the theory further.
I think you're right in saying that these are not hard-and-fast rules.
I think the point is that, for a new theory to become more favored than the current leading theory, the new theory must be consistent with at least as much scientific evidence as the leading theory. From there, the value of predictions is that they give a path for strengthening the theory further.
I think you're right in saying that these are not hard-and-fast rules.