Humans as animals
Yes, it is literally factual and true that human beings are animals within the animal kingdom, but it doesn't always feel like that, so the job of keen philosophers is (and always has been, and probably always will be) to reconcile the way it feels to be human with the scientific facts about human nature. In this case, Marcuse attempts to reconcile the abstract concepts of economy and progress to the very carnal, instinctual urges of sexual power and erotic release. By reframing economic issues as biogenetic, Marcuse proves that money and economy are essentially extensions of animal nature.
Economy as the thrust of progress
The connection between civilization and economic progress is shown to be technology. Instead of viewing technology as a kind of essential goal, which was very popular at the time, Marcuse describes technological progress as a specific kind of progress with a specific shape; to improve the quality of life for one's civilization through luxury and economic power. It isn't just "technology for technology's sake," but rather, civilizations move forward when particular people are successful at selling a technological product for money, so they can become rich and mate with ideal partners.
Money and sex
As noted, Marcuse's theory hinges on this essential connection, the intrinsic connection of money and sex. Money is the right for sexual (or social) power. Money is closely associated to human hierarchies, and being poor is designed specifically to reduce power (says Marcus). Not only does money lead to more successful mating efforts by nature, the efforts of capitalism also underscore that dynamic by shaming poor people as if it is their own fault that they are poor. The connection between economic power and sexual attractiveness is ancient and well-noted. The motif has a brilliant depiction in the Revelation of John in the image often called "The Beast and the Harlot," where a wicked woman is bedded with a dragon because of his enormous wealth.
The utilitarian subjugation of the poor
Marcuse's theory also shows that the concept of poverty has been subtly informed by capitalistic interests through time. Instead of seeing the poor as essentially equal, but disenfranchised, or as Christianity depicts the poor, as worthy of help and divinely important, the efforts of capitalism show poverty to be something altogether different. The narrative of capitalism is that smart and responsibile people naturally succeed (which is obviously not how that works), while stupid or irresponsible people fail. By shaming poor people into working harder, Marcuse says that the means of production can be improved. Poor people have no reason to work hard when earning business owner's money, but by urging them to believe that their work is ethical and will lead to a better life, work can be ensured.
Capitalism and Darwinism
At its root, Marcuse's theory hinges on social Darwinism. By observing that humans are essentially animals, the selectivity of nature is shown to be Darwinian. Ideal women are most likely to select partners who are powerful and wealthy, because those are the traits that their animal nature is most attracted to. This is obviously a somewhat tactless depiction of the dynamic, because women are also eligible to participate in the economy, and the selection process is complex and nuanced, but Marcuse's theory still draws a valid connection between business success and reproductive success. The effect is that capitalism is the survival of the fittest, where "fitness" is the ability to earn money through ingenuity. Also, physical attractiveness is bred into the higher class, because sexually attractive mates are most likely to mate with top-tier members of society.
