Suppose we have a theory, T, that predicts our current observations. T has some property, P, that might also be possessed by alternative theories. Can we say that P is inferred by our observations?
Not necessarily. For P to be scientifically inferred from observation, we would have to be assured that P is scientifically testable. That is, we should be able to design an experiment that tests P independent of theoretic context because P itself predicts the experiment's result. If we cannot do this, then P may simply be a notational artifact. Rather than being a property of the observed world, P would be nothing but an artifact of how we describe it.
This is a problem that applies to both evolution and intelligent design (ID). Evolution is a category of theories that explains the evolution of living systems from physical principles. There are many theories, some of them mutually exclusive and competitive. What we can say is that predictive evolutionary theories have been confirmed by experiment.
ID is also a metatheory. Any scientific theory that accounts for features of living systems as the results of design and manufacturing by an intelligent agent would belong to the ID metatheory. To date, no scientific theories of ID have even been proposed, let alone confirmed by experiment.
The subject of metatheories will be relevant to my next post.