"There are no small problems. Problems that appear small are large problems that are not understood. Instead of tiny details unworthy of the intellectual, we have men whose tiny intellects cannot rise to penetrate the infinitesimal. Nature is a harmonious mechanism where all parts, including those appearing to play a secondary role, cooperate in the functional whole. In contemplating this mechanism, shallow men arbitrarily divide its parts into essential and secondary, whereas the insightful thinker is content with classifying them as understood and poorly understood, ignoring for the moment their size and immediately useful properties. No one can predict their importance in the future." From Advice for a Young Investigator
Cajal's precise understanding of anatomy is echoed in modern visualization techniques. His drawings of neurons captured the spidery outgrowths called dendritic spines, the site wehere each neuron talks to its neighbors.
left: Cajal Legacy Instituto Cajal (CSIC), Madrid | right: Courtesy Joel Mancuso (Gatan Inc) and Thomas Deerink and Mark Ellisman (NCMIR, UCSD)