“If QED [quantum electrodynamics] is merely a phenomenology, how can one account for its remarkable quantitative success? The answer is intimately related to one of its most characteristic features, renormalizability. Because of this, short distance, high energy effects in QED can be absorbed into a finite number of measurable masses and charges. For the first time in the history of physics, there exists a theory which has no obvious intrinsic limitation and enables us in principle to calculate physical phenomena to any accuracy we need in terms of a few measurable parameters such as the elementary electric charge e [fine structure constant] and the electron mass m. Thus the detailed high energy structure of the ultimate theory is irrelevant to the analysis of low energy phenomena except insofar as it determines these parameters. [Quantum Electrodynamics]”