differences between theory and study

Theory is something that is believed to be true because experiments and/or Maths have proved it to be true or because no better explanation currently exists. Chaos Theory, for instance, is the idea that seemingly unrelated events actually work in tandem to an inevitable end. This has been proven true in many cases but remains unproven in far more cases. The theory of evolution, similarly, is simply the best available theory. It contains too many scientific loopholes to ever be conclusively proved to be true, in any specific case.

Study is a very general term. It means disciplined observation. Study includes research, theory, and principle, but is not limited to these things. Research, theory, and principle, are the results of study. However, study also results in the dismissal of certain types of research, theory, and principle. For instance, even rudimentary study of eugenics dismisses the value of research, theory, and principle underlying eugenics and/or associated with eugenics.