From the pen of Spanish Nobel Laureate, Santiago Ram n y Cajal (1852-1934), the visionary of science nicknamed "Don Quixote of the Microscope," comes this essay, based on a 1905 lecture during the celebrations that marked the tricentennial of the "Ingenioso hidalgo de La Mancha." It is a mighty knock and a romantic fustigator against the awkward materialism that has been reigning in modern times. The text bespeaks the Cajalian spirit in the best possible...