The Maxwell-Heaviside theory of electrodynamics is now well over a century old, and is actually a serious truncation of Maxwell's 1865 theory of 20 equations in 20 unknowns (those are specifically listed in the original published paper in 1865). Because it was “tainted” with a higher group symmetry algebra (quaternions), even Maxwell himself came under intense pressure to simplify it, after the publication of the first edition of his famous Treatise in 1873. Consequently, Maxwell was rewriting and greatly “watering down” his own Treatise, having finished rewriting and greatly reducing some 80% of it at the time of his death in 1879. The second edition and third edition, therefore, are NOT the original Maxwellian theory, but a very serious truncation.

The further great “simplification” occurred by several scientists after Maxwell's death, in the 1880s, and notably by Heaviside, Hertz, and Gibbs. The equations taught today at university as “Maxwell's theory” are pale shadows, and those equations themselves are actually the equations and notations of Heaviside, further “symmetrically regauged” by Lorentz (which very neatly threw out all COP>1.0 EM systems taking their excess energy from the vacuum in the form of free asymmetrical regauging). At the time these altered Maxwell equations were adopted in general, it occurred in a short “debate” (mostly in the journal Nature) where the vectorists simply discarded the quaternists' work, etc. It was not done by “sweet science”, but by sheer dogma and individual preference for“simplicity”.