The linguistic domain as a domain of orienting behavior requires at least two interacting organisms with comparable domains of interactions, so that a cooperative system of consensual interactions may be developed in which the emerging conduct of the two organisms is relevant for both. The specifiability through learning of the orienting interactions allows for a purely consensual (cultural) evolution in this domain, without it necessarily involving any further evolution of the nervous system; for this reason the linguistic domain in general, and the domain of self-consciousness in particular, are, in principle, independent of the biological substratum that generates them.

Interaction is the mode of life of living organisms. Each must feed on its environment, ingesting chemicals or other organisms. This is something more than "interaction", it is activity directed towards the environment. Since the organism must be selective in what it ingests, it needs to discriminate among the entities in its environment. From very primitive forms of discrimination, the sensory mechanisms of organisms have evolved into the senses of man, interpreted by an internal cognitive apparatus, memories of past experiences, and an ability to take rational decisions. By "rational" I mean activity that achieves intended results because it is based on a reliable understanding of the nature of the environment. In interacting with each other to carry out tasks jointly, men have further developed language, leading to a shared understanding of the environment. This shared understanding is knowledge.

But some of our moral behaviors, if not sentiments, almost certainly evolved. Evidence for that comes from finding parallels between the behavior of our own species and that of our relatives.

The mammalian record thus confirms our statement that any animal which is not too strongly conditioned by some special sort of experience is capable of responding to any adequate stimulus. This is what we find in the more uninhibited segments of our human species, and this is what we find among young children who are not too rigorously restrained in their early sex play. Exclusive preferences and patterns of behavior, heterosexual or homosexual, come only with experience, or as a result of social pressures which tend to force an individual into an exclusive pattern of one or the other sort. Psychologists and psychiatrists, reflecting the mores of the culture in which they have been raised, have spent a good deal of time trying explain the origins of homosexual activity; but considering the physiology of sexual response and the mammalian backgrounds of human behavior, it is not so difficult to explain why a human animal does a particular thing sexually. It is more difficult to explain why each and every individual is not involved in every type of sexual activity.

For our own species, evolution occurs mostly through our behavior. We innovate new behavior to adapt.

"Most instincts are allied to specialized organs, it is true, but it is nonetheless true that perception and acquired behavior, including the higher types of operative intelligence, do, in a more supple way, manifest certain functional possibilities or "reaction norms" of the anatomical and physiological structure of the species. In a word, the general coordinations of action upon which the building up of most basic types of knowledge is conditional, presuppose not only nervous coordinations but coordinations of a much more deep-seated kind, those which are, in fact, interactions dominating the entire morphogenesis."

Our humanity rests upon a series of learned behaviors, woven together into patterns that are infinitely fragile and never directly inherited.

The origin of the human condition is best explained by the natural selection for social interaction — the inherited propensities to communicate, recognize, evaluate, bond, cooperate, compete, and from all these the deep warm pleasure of belonging to your own special group.

Ethologists and comparative psychologists have discovered a host of refined adaptations in animal behavior during the past few decades. Food-finding, avoidance of predators, and behavioral adaptations to environmental stresses, including constructing shelters, nests, and burrows, all involve impressively versatile tactics on the animal's part, rather than rigid, stereotyped reflexes. Social behavior, especially courtship and care of developing young, call forth an efficiently tuned and controlled matrix of interactions among many different and potentially conflicting behavior patterns. Animal orientation and navigation have provided several striking examples of previously unsuspected modes of perception. Finally, the versatility of animal communication used to coordinate group activities has implications that can only be described as revolutionary. The flexibility and appropriateness of animal behavior suggest both that complex processes occur within their brains, and that these events may have much in common with our own conscious mental experiences.

Behavior evolves through natural selection, just as anatomy does. Hence if sex is enjoyable, natural selection must have been responsible for that outcome.

Our language evolved as a way of gossiping.

We can also say that language is a domain of recursive linguistic co-ordinations of actions, or a domain of second-order linguistic co-ordinations of actions. We human beings also co-ordinate our actions with each other in first-order linguistic domains , and we do so frequently with non-human animals.

It is now generally accepted that the roots of our ethics lie in patterns of behavior that evolved among our pre-human ancestors, the social mammals and that we retain within our biological nature elements of these evolved responses. We have learned considerably more about these responses, and we are beginning to to understand how they interact with our capacity to reason.

The evolution of life is analogous to the evolution of language. For example, there are several languages based on the Roman alphabet of only 26 letters. Yet by arranging these in different orders, we’ve added several hundred thousand words to English since the 5th century, and many of them were completely new. The principle is the same in genetics. There are millions of named and classified species of life, all of them based on a variable arrangement of only four chemical components. For another example, we know that Spanish, Italian, French, and Portuguese all evolved from Latin, a vernacular which is now extinct. Each of these newer tongues emerged via a slow accumulation of their own unique slang lingo –thus diverging into new dialects, and eventually distinct forms of gibberish such that the new Romans could no longer communicate with either Parisians or Spaniards. Similarly, if we took an original Latin speaking population and divided them sequestered in complete isolation over several centuries, they might still be able to understand each other, or their jargon may have become unintelligible to foreigners. But they won’t start speaking Italian or Romanian because identical vocabularies aren’t going to occur twice.