"As the decades have passed, one by one all his theories have been corroborated using modern techniques, and the main hypotheses that Cajal postulated have become universally recognized as biological laws: The neuron theory; the law of the dynamic polarization of the neuron and the principle of connectional specificity."
January 1, 1970
https://en.wikiquote.org/wiki/Santiago_Ram%C3%B3n_y_Cajal