Maxwell's equations reveal an interdependency between electric and magnetic fields, inasmuch as a time varying magnetic field generates a rotating electric field and vice versa. Furthermore, the equations predict that even in the absence of any sources one can have self propagating electric and magnetic fields, so called electromagnetic waves.
However, is it correct to say that although Maxwell's equations show that electric and magnetic fields are interdependent, they do not imply that the two are different aspects of the same underlying physical phenomenon?!
Given this, is it then correct to say that it is not until one takes into account special relativity that it becomes clear that electricity and magnetism are different manifestations of the same underlying phenomenon?
Indeed, if one considers a frame of reference in which only an electric (or magnetic) field is observed, then, upon a Lorentz transformation to another frame of reference, it is found that one will observe a combination of electric and magnetic fields. This implies that the two are not independent of one another, since there is no observer independent manner in which one can separate electric and magnetic fields, hence implying that they are manifestations of the same underlying field - the electromagnetic field?!
In essence, my question is, can one deduce purely from Maxwell's equations that the electric and magnetic fields are actually "the same" field, or is this (necessary) unification not explicitly confirmed until one takes into account special relativity?