<p> The Marquis de Sade became famous, or infamous depending on one's perspective, for the ferocious depictions of sexual predation which are found throughout his literary works, and consequently, the character of the sexual predator is indispensable to understanding the author's philosophical standpoint. For Sade, the laws of nature determine the sex of the individual, but they also require him or her to satisfy a set of physical needs which reject the masculine/feminine binary as often as they embrace it. This blurring of the lines between masculinity and femininity is thus characteristic of the Sadian sexual predator who must constantly seek satisfaction for his needs regardless of social and religious constraints on his behavior and on the sex of his victim. When examining the myriad variations on this character in Sade's work, it becomes clear that he has transferred the natural law of &ldquo;survival of the fittest&rdquo; from a purely physical to a highly intellectual concept and, in so doing, has created a predator who uses mental as well as physical strength to dominate his victim. I, therefore, propose that masculinity mixes fluidly with femininity when examined through the lens of the predator and that by investigating the hierarchy of predator versus prey, the mutability of gender at both extremes of the predatory relationship, and the description of specific acts of predation, it is possible to deconstruct the gender differences through the strict adherence to the laws of nature observed by Sade's sexual predators.</p>