The important bit here is being able to very clearly distinguish between "EXISTS" and "DOES NOT EXIST" (does not qualify as extant).

(IFF) you have no empirical evidence (and cannot demonstrate some logical necessity) of "spiritual-wind" (THEN) you cannot categorize "spiritual-wind" in the "EXISTS" category.

Certainly there might be (currently undiscovered) things that will be said to "EXIST" in the future, and we might even RETROACTIVELY say they "EXISTED" "before" they were "discovered", but up-to-and-until that day when they are empirically verifiable (and or demonstrated to be logically necessary) we cannot say "spiritual-wind" "EXISTS".

Radio waves are a good example of this.