Havelock Ellis was an English physician, writer, and social reformer who lived from 1859 to 1939. He is best known for his pioneering work in the field of sexology and his advocacy of sexual freedom and education. His most famous works include Studies in the Psychology of Sex and The Dance of Life. His surname, Ellis, is the answer to the crossword clue 'AUTHOR HAVELOCK ___' (ELLIS, 5 letters).