Rational Agency

Genesis presents a figurative account of the development of rational agency. But what exactly does "reason" mean? Reason can be defined as the ability to use knowledge to solve problems, connect things, and develop concepts. It can mean planning far ahead and carrying out a series of sequential steps. Reason can mean the ability to think through the likely outcomes of an action, decide whether the likely benefits are worth the risks involved, and make a conscious decision on the most useful action.

Rationality can also mean the ability to acquire knowledge and apply it intelligently to one's behavior. We use knowledge to learn, to teach, 

innovate, and to respond flexibly to new situations. We interpret the world that surrounds us, draw conclusions, and initiate actions in response to it. To some extent, we even change the world to suit our specific, consciously determined purposes.

It is obvious that humans did not acquire rationality in a single bite, as in Genesis. As with language, the emergence of rationality is a long evolutionary process rather than a single evolutionary event in time. The evolution of rational action is, in large part, what human evolution has been about. Over time, humans have learned to control their environment and adapt themselves to its demands. Communication, cooperation, and other technical and cultural developments have been essential in this process. They are a part of rational life.

Much of human behavior has left no archaeological traces. Nevertheless, anthropologists succeeded in tracing human behavior through archaeology. The clearest evidence that humans acquired rationality is the production and use of stone tools. Anthropologists have found millions of these tools across the continents, representing different techniques and cultures, providing clear evidence of human cultural and cognitive evolution. Anthropologists divide these tools into different types made with a variety of techniques, starting with the very simple Lomekwian and Oldowan tools. These tools provide concrete evidence for the evolution of rationality.

Rationality can also mean working step by step, with means to an end. Consider, for instance, early humans and their production and use of stone tools. First, there is hunger and the desire to eat some meat. The process continues with the realization that you need a cutting tool for the meat. Then the need arises to have a hammerstone to knap the cutting tool. After that, it is necessary to look for the necessary materials to produce the cutting tool. The tools must then be made by striking the stones repeatedly. Then they must be applied to a carcass. Finally, the hunger can be satisfied. 

The manufacturing of tools represents a key feature that distinguishes the human species from animals. With these early Lomekwian and Oldowan tools, a fundamental change in the technical behavior of early humans occurred. Humans moved from working soft material and using natural stones to knapping hard rock in order to intentionally detach flakes.

Oldowan tools were made by striking sharp stone flakes from a stone core held through direct blows with a harder ”hammerstone”. The intentional chipping of stones was used to create cutting, chopping, and scraping edges. These tools were used to cut meat from animal carcasses so it could be eaten: some animals were too large to be torn by hand and instead required stone tools for their slaughter. The stone cores were probably also used to crush the bones and extract the marrow.

                                                                                                          Acheulean stone tools were manufactured through a complex operational sequence.

Acheulean tools were used for processing animals for food: Skinning, dismembering, and defleshing. Scrapers were used for cleaning animal flesh, and cleavers were used for breaking animal bones during slaughter to get to the marrow. Fresh bones are difficult to break without a hammerstone. Hand axes are excellent for massive and continuous butchering because they provide the force and leverage needed for cutting and dismembering. Other uses included cracking nuts, digging up wild roots, and processing plant matter. Some tools appear to have been used for woodworking.

Acheulean tools were apparently purposeful and sometimes artfully shaped for the functions they were intended to perform. Stone was shaped into cleavers, scrapers, and picks. The distinctive hand axe was carefully shaped by removing flakes from both faces of a large flake or small cobble to create a tool with a symmetrical shape and a tapering point with sharp edges. These tools are called “bifaces” because the stone is fashioned on both sides to obtain a symmetrical appearance.

The making of tools shows foresight and skill. Human ancestors were able to make technical considerations about the properties of physical objects. It is clear that they understood that there is a certain sequence of motor actions necessary for making tools. First, succesfull knapping depends on controlling the pattern with which force is applied to a stone. One must examine the surfaces of the core to direct powerful blows to specific areas on the target core. The blows must not alter the shape of the core in such a way that further detachments are not possible. A carefully controlled, sharp blow of the hammer on the core is required to initiate fracture. To properly flake stone, one also needs to look for acute angles on the core edges from which the splinters can be detached and apply the proper amount of force. The knapper must also learn good holding positions for the core. He must understand the fracture mechanics of the stone raw material.

Acheulian tools were formed through a long knapping sequence (operational sequence, chaîne opératoire). This requires a remarkable increase in the technical skills of the maker, which requires a high degree of planning and foresight. The production of Oldowan tools is less complex than that of the Acheulian tools and placed fewer demands on their makers. Based on experimental replication studies, making Acheulean handaxes requires more than four times as many cognitive decisions and procedures as making Oldowan tools. While learning the skills to make Oldowan technology for a modern knapper requires only a few hours of practice, the Acheulean technique requires hundreds of hours. Deliberate practice and teaching were required. But even the production of Oldowan stone tools requires visuo-motor coordination and the capacity to focus attention on the production of the tool.

Read the full interpretation in my book the Genesis of Humanity.