The desire for a complete life is one of many desires that belong to our biological human nature. As I argued more fully in my book Darwinian Natural Right, natural selection has shaped human nature to express at least twenty natural desires that are manifested in diverse ways in all human societies throughout history. Human beings generally desire a complete life, parental care, sexual identity, sexual mating, familial bonding, friendship, social ranking, justice as reciprocity, political rule, war, health, beauty, wealth, speech, practical habituation, practical reasoning, practical arts, aesthetic pleasure, religious understanding, and intellectual understanding.

To illustrate what I mean, consider the first two desires on my list — a complete life and parental care. Human beings generally desire life. Like other animals, they pass through a life cycle from birth to maturity to death. Every human society is organized to manage the changing desires associated with this life cycle, which passes through distinct stages such as infancy, childhood, adolescence, adulthood, and old age. Children, adults, and the elderly have different desires, and to satisfy those desires they must fill different roles in society. Human beings will risk their lives for a good cause. And yet they generally agree that to be fully happy one must live out one’s natural lifespan.

Human beings also generally desire to care for children. Human life would be impossible without parental care of the young. A large portion of the activity and resources of every human society is devoted to parental care and familial life generally. Children desire the care of adults. And although parental caregiving is often onerous, most human adults desire to provide such care, especially for those children to whom they have some affiliative bond — either those to whom they are related by kinship or those to whom they have developed some adoptive attachment.

Such desires are so deeply woven into the adaptive complexity of human nature that they are not likely to be radically changed by biotechnology. On the contrary, we should expect that biotechnology — as well as all forms of technology — will be used to satisfy those natural human desires: to preserve life, to assist parental care, to improve one’s sexual chances, and so on. Since our natural desires provide our ultimate motivations for action, it is hard to see why we would use biotechnology to abolish them.

Biotechnology is also an expression of our natural desire for practical arts. Every human society depends on making and using tools to control natural