“When Pavlov began studying the behavior of great apes in his laboratory in the last years of his life, he was already talking quite definitely about a special type of association that can be considered concrete thinking: ‘And when an ape builds his tower to get a fruit, then you cannot call it a ‘conditioned reflex.’ This is a case of knowledge formation, of capturing the normal connection of things. This is a different case. Here it must be said that this is the beginning of knowledge, of understanding a constant connection between things—what underlies all scientific activity, the laws of causality’” (Krushinsky 1986, p. 10).

Human causal models are universal and allow the construction of action programs that are applicable to all situations encountered by a culture-society. In this respect, humans differ from animals, which construct empirical models that are only valid for a specific situation and create probabilistic rather than deterministic action programs (cf. Krushinsky 1986, p. 11).

Knowledge is usually defined as “justified true belief.” However, knowledge cannot be reduced to belief without action. Belief is only justified if it enables action.

“Man is in a position to act because he has the ability to discover causal relations which determine change and becoming in the universe. Acting requires and presupposes the category of causality. Only a man who sees the world in the light of causality is fitted to act. In this sense we may say that causality is a category of action. The category means and ends presupposes the category cause and effect” (Mises 1996, p. 22).

As a cause-effect model or pattern of events, knowledge also implies a set of skills, that is, an action program.

The evolution of proto-humanity was based on the self-reproduction of its populations. The ability to reproduce is a property of life, but a cell or an organism can only reproduce as a whole: selection cannot act within them. A population as a collection of organisms of one species in a relatively closed habitat is the actual sphere of action of natural selection: the self-reproduction of a population is not based on the reproduction of the whole, but on self-renewal, on the alternation of generations of individuals (Berg 1993, p. 251).

Early human populations remained at the mercy of natural selection, but with the accumulation of culture, the self-reproduction of populations changed its character: populations became cultures-societies that reproduced themselves not only through natural but also through cultural mechanisms—not only through the transmission of genes and the interaction of organisms with the habitat, but also through the transmission of meanings and interaction of humans with the domus. Natural selection was gradually supplemented and expanded by cultural selection. Modern man is the result of a mixture of natural and cultural selection, he represents the unity of genotype and meaning type.

During the millions of years of mixed selection, the evolution of practices went hand in hand with the evolution of organisms, ensuring the adaptation of proto-human populations to a changing natural and cultural milieu—to changes in climate and natural landscape, as well as to changes in the landscape of meanings. Mixed selection has left clear traces in the human body.

“…Culturally accumulating communicative repertoires put selective pressures on genes for communicating: they pushed down our larynx to widen our vocal range, drove axonal connections from our neocortex down deep into our spinal cords to improve the dexterity of our hands and tongues, whitened the sclera of our eyes to reveal our gaze direction to cue others, and endowed us with reliably developing cognitive skills for vocal mimicry and communicative cueing, like pointing and eye gaze” (Henrich 2016, p. 251).

The brain, as a central part of the nervous system, plays a key role in the metabolism of primates and especially humans, in whom the second signaling system is built upon the first. A larger brain was crucial for the accumulation of culture. The modern human brain consumes 20 to 25 percent of an organisms’ metabolic energy, as opposed to 8 to 10 percent in other primates and only 3 to 5 percent in other mammals. To increase brain mass, it was necessary to reduce the mass of other metabolically expensive tissues—primarily the digestive organs—which was achieved by changing the diet (cf. Smil 2017, p. 23).

Lighting a fire and cooking on it are not instinctive animal actions; they are practices passed down from generation to generation through learning. And these practices, which largely moved the digestion process outside the human body, greatly influenced the way our jaws and digestive system are constructed. Henrich writes (2016, pp. 65-9), referring to the work of Richard Wrangham, that mastery of fire radically reduced the energy used to function the digestive organs, which in turn affected the structure of the nervous system and the volume of the human brain, which was a prerequisite for the further accumulation of meanings. James Scott says, that mastery of fire not only led to changes in the human body, but also allowed man to greatly expand his ecological niche. Humans used fire to modify natural landscapes, thus creating conditions for the reproduction of animals and plants of interest to them. Over time, this led to a concentration of favorable flora and fauna, the emergence of more abundant and predictable food sources within walking distance of human dwellings, and subsequently to sedentarization and domestication (cf. Scott 2017, pp. 58-60).