The theater has traditionally been a male domain. The ranks of authors, directors, and even actors have long been overwhelmingly dominated by men. In Western drama, no women playwrights have gained admittance to the literary canon. While never absolute, the relative exclusion of women from dramatic authorship is even greater when the type of theater in question is tragedy. Carol Gelderman asks bluntly: "Why is it that no woman has ever written a great tragedy?". A number of explanations have been put forward that suggest deep-seated links between men and tragedy: Susan Gilbert and Susan Gubar find that "the structure of tragedy reflects the structure of patriarchy" and that Western tragedies almost invariably focus on a male "overreacher". Sue-Ellen Case perceives close links between tragedy and male sexuality. Gelderman views tragedy as a natural tool for male self-assertiveness. The most categorical, albeit least enlightening, response comes from Voltaire who, when asked why no woman had ever written a tolerable tragedy, replied, "Ah, the composition of a tragedy requires testicles".