We are accustomed to say that every human being displays both male and female instinctual impulses, needs, and attributes, but the characteristics of what is male and female can only be demonstrated in anatomy, and not in psychology. Where the latter is concerned, the antithesis of sex fades away into that of activity and passivity, and we far too readily identify activity with masculinity and passivity with femininity, a statement which is by no means universally confirmed in the animal world.
