Reproduction theory has changed little over time, and its language continues to mediate people and their procreativity. The two main issues, the value of gender and the control of procreation, persist throughout a considerable history of human reproductive thought. Within some of the earliest philosophical writings from classical Greece lie the first coherent theories of human reproduction. Moreover, treatises such as Aristotle's on human reproduction form the basis of an approach to understanding regeneration in a way that values male contributions and their stated worth over those of females. These views, which include male seed theory and the notion of the homunculus (the entire human form is contained in a sperm), continued well into the sixteenth century in Western Europe. They also served as precursors to underlying philosophies of reproduction developed during the scientific revolution, which extend into contemporary debates surrounding new reproductive technologies and genetic engineering. Within new reproductive technologies women's breeding capacities are emphasized over experiences and rights of maternity. Embryos are separated from the pregnant woman and become the subject of public property disputes. Men gain reproductive options that increase their chances of genetic continuity. In addition to gender bias exist concerns with the general fragmentation and control of humanity. Also, the site and purpose of reproduction have radically shifted, and genetics has become a determinant of human relations and human value.
The first theories of human reproduction were limited to what could be observed outside the body. The visible elements of reproduction--semen,