Oliver Heaviside and Sir William Thomson stand in such contrast that the life of each serves to illuminate the life of the other. Thomson's talents, which were recognized at an early age, were cultivated with possibly unsurpassed educational opportunities, whereas Heaviside had scarcely any educational opportunities and was essentially self-taught. Nevertheless, Heaviside's published and unpublished works suggest that the breadth and depth of his learning were more or less comparable to Thomson's. Being an outstanding student at Cambridge brought Thomson in (...) contact with scientists of the first rank, and he learned without effort how to get along with his peers. That pleasing quality was essentially absent in Heaviside, whose personality was as prickly as a porcupine, almost without grace. But underneath this rough exterior was a noble genius who never exploited his rare talents to his own advantage, but instead dedicated them to learning the Truth for its own sake. As to personal temperament, educational opportunities, professional and social activities, Heaviside and Thomson were poles apart. But they maintained a correspondence which is significant, and Thomson's assistance to Heaviside is noteworthy. (shrink)