The world is not divided into sheeps and goats. Not all things are black nor all things white. It is a fundamental of taxonomy that nature rarely deals with discrete categories. Only the human mind invents categories and tries to force facts into separated pigeon-holes. The living world is a continuum in each and every one of its aspects. The sooner we learn this concerning sexual behavior the sooner we shall reach a sound understanding of the realities of sex.
~Alfred Kinsey in The Sexual Behavior in the Human Male, 1948