The wor homophile is an alternative to the word homosexual, preferred by some because it emphasizes love ("-phile" from Greek φιλία) over sex. Coined by the german astrologist, author and psychoanalyst Karl-Günther Heimsoth in his 1924 doctoral dissertation "Hetero- und Homophilie", the term was in common use in the 1950s and 1960s by homosexual organisations and publications; the groups of this period are now known collectively as the homophile movement.