Under scientific naturalism the reality of events depends on their conformity to laws and repeatability under prescribed conditions, etc., so the elements that make them up, fields, molecules and so on are all perfect instances of a well-defined type and hence they are ideal. This kind of naturalism is idealism without knowing and without ever admitting it. Under idealism events depend on affinities which ultimately go so deep as to encompass the entire field of reality, and hence events are never perfectly repeatable, any such notion makes no sense at all; if you admitted fields and molecules you would have to add that each instance was incomparable to any other instance precisely because the context will have changed. Thus idealism ends up in the situation thought to be definitive for materialism. Both are ideas and the dialectic between them is a matter of turning a key. The aim is to align it perfectly with the keyhole. That's the most you can do. Pushing it in and opening the lock must come from some other agency outside the system.