This booklet revives a little known document written in February 1915 by the neuroanatomist and Nobel laureate Santiago Ramón y Cajal (1852–1934), concerning the political, sentimental, and ideological trends that would dominate the European scene in the aftermath of World War I. With his remarkable acumen, Cajal predicted the outburst of World War II and the consequent formation of international alliances. The only values of worth in the human species, according to the author, are Science and Art, while its bestial remnants underpin the incessant thirst for a new bloodpath every twenty or thirty years. Future generations may only surpass us in that, through the progress of physiology and psychology, they may be able to comprehend the cruel and wicked human nature, without though emending it. One explanation for all this is the slow pace of the evolution of nerve cells in the human brain. Similar ideas echoed in the writings of other biomedical scholars of the twentieth century, including Charles Richet, Sigmund Freud, Albert Szent-Györgyi, and Frank Macfarlane Burnet.