What I meant to say is that if we require science to require all theories to be empirically testable, then philosophical naturalism is not a scientific view, and further under the same arguments for why ID should be kept out of the classroom apply to naturalism as well.
Furthermore, the claim that all life came about by unguided evolution is therefore not scientific either, as it cannot be falsified. Assertions of teleology, and similarly, lack of teleology, would fall under this umbrella. — Paulm12
In a rational humanity devoid of hypocrisy, in a word, yes.
There are two typical understanding of "science": One is any branch of learning. Here mathematics can be construed a science, as can technology, archeology, etc. But then so too can mythology (it’s a branch of learning). Or, else, fartology as the branch of learning how and when to properly fart. The other understanding is that it is shorthand for the empirical sciences. Here, all conclusions are inductively obtained from empirical data that can be replicated by others - lest it be illusory or else outright deception - itself derived from falsifiable hypotheses which the data either evidences/verifies (but never conclusively proves) or else falsifies (thereby conclusively proving the one or more hypotheses false). Without this system/methodology that incorporates falsifiability, anything could go: including an in-depth theory/paradigm accounting for all aspects of the universe in terms of invisible unicorns with magical powers that surround.
Where there is confusion between the two understandings of science, the empirical sciences lose their efficacy and, in turn, their validity. At the very least in the public eye.
Since this is a philosophy forum, the methodology of the empirical sciences is itself founded upon philosophical principles. Nevertheless, in so far as these amount to the methodology of the empirical sciences, the empirical sciences will themselves be utterly distinct from the branch of learning termed philosophy at large. The empirical sciences are also greatly reliant upon non-empirical-science branches of learning, in particular that of mathematics (here first and foremost in terms of statistical analysis of data).
Because the empirical sciences are limited, in part, to data that can be replicated by any other, they by default cannot be applied to things such as the reality of anything spiritual - if there might be one - which by its very nature of so being (if it in fact to any extent occurs) is not ubiquitously profane and thereby equally observable by all in principle.
Gravity and natural selection are in and of themselves theories regarding broad spectrums of data obtained or else confirmed by the empirical sciences - but are not in and of themselves applied empirical sciences. Nonetheless, as theories they are falsifiable by potential empirical data (a replicable observation of apples that move upward into the skies or, else, a replicable observation of a lifeform in the fossil record devoid of any taxonomical lineage - like the discovery of a fossilized griffin), and as theories are furthermore evidenced/verified by all empirical data.
Not that this presents a complete picture, nevertheless:
Neither philosophical naturalism nor Intelligent Design can be empirically falsified via observable data that is necessarily replicable by all others. Neither are, nor can be, integral aspects of the empirical sciences proper. But both can be deemed sciences, by those who uphold them, in the generalized sense of “branches of learning”.
So no, Intelligent Design is not a valid scientific theory (if one is addressing the empirical sciences).