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Tallis in Wonderland
Raymond Tallis makes much out of human tool use.
A recurrent theme of these columns has been the fundamental difference between humans and the rest of the natural world. Not long ago, those who, like me, wanted to highlight these differences, could appeal to the use of tools; to the way that we employ inanimate objects to enhance the capacities of our bodies and solve problems. In recent decades, evidence has emerged that seems to challenge this basis for our claim to uniqueness.
For some, the assertion that animals do not use tools has always been undermined even by ordinary observations of the lives of the beasts. Are not beavers’ dams, birds’ nests, bees’ honeycombs, and spiders’ webs tools of a sort? Not in the sense that matters. After all, in contrast to the human equivalents, the construction and utilisation of all these items is instinctive, and obligatory for all members of the given species. More to the point, they all do it in roughly the same way, and at the same biologically dictated time in the life-cycle of the animal, and, as in the case of birds and many other species, at a biologically prescribed time of year. There is nothing bespoke or elective about such activity: it is the result of preprogrammed suites of actions. Birds don’t decide to build nests and then work out how to do it. Social insects such as bees don’t choose to work together to achieve a common end, poring over plans for hives. There is merely a dovetailing of automaticities. Nest-building and web-weaving are clear examples of what Daniel Dennett has called ‘competencies without comprehension’: executing something that has a clear biological purpose without that purpose being explicitly entertained by the beast in question. This is in sharp contrast with, say, the building of a house, which is driven by an explicit vision of the end product and its purpose, and of the processes necessary to achieve it, shared among those who work to create it.
In recent decades, however, there have been increasingly frequent reports of animal behaviour that looks to be closer to human tool use. Here are some examples:
a) Chimpanzees fashioning twigs into ‘fishing rods’ by stripping them of leaves to capture termites their hands cannot reach;
b) Gorillas using sticks to rake in food;
c) Macaque monkeys washing potatoes and grain to make sure they’re clean;
d) Primates hurling sticks or rocks as weapons to intimidate rivals;
e) Orang-utans employing large leaves as umbrellas;
f) New world monkeys using stones to crack nuts;
g) Galapagos finches deploying cactus spines to skewer insects in hollows;
h) Dolphins protecting their noses with sponges when they probe the sea floor;
i) Octopuses collecting coconut shells to protect themselves;
j) Kites and falcons picking up burning sticks and dropping them on to dry grass to set fire to it with the aiming of flushing out small animals.
There have been rare examples of even more sophisticated tool use. For example, a study of capuchin monkeys identified what is called ‘secondary’ or ‘sequential’ tool use: the employment of tools to make or obtain tools. M. Mannu and E.B. Ottoni observed the monkeys using smaller stones to loosen bigger quartz pebbles which could then be used as hammers to open fruit or seeds (‘The enhanced tool kit of two bearded capuchin monkeys in the Caatinga: tool-making, associative use, and secondary tool-use’, American Journal of Primatology, 71(3), March 2009). Importantly, the monkeys’ use of the stones seemed to be elective and multi-purpose, deliberately using the stones differently in different contexts. While the pickings were slim – the researchers observed a grand total of three instances of this behaviour in seven hundred hours of filming – the findings might seem to be another setback for those, such as myself, who appeal to tool use as a marker of the fundamental gap between ourselves and the other inhabitants of the animal kingdom.
Vorsprung Durch Technik
It is not yet time, however, for human exceptionalists to throw in the towel. The gap between tool use in animals and in humans remains vast. To establish this, it is only necessary to look at human tool use with an unpeeled gaze.
Firstly, animals seem to exploit only naturally occurring objects. Human tools, by contrast, are frequently manufactured, often using materials brought from elsewhere, even composite ingredients such as alloys. Such tools are synthesised rather than simply lying to hand, waiting to be bumped into. Even where humans use naturally occurring materials, they are transformed in ways that are not seen in animal behaviour. Think of the flour that goes into the making of bread. This transformation is evident even in the case of very early tools such as carefully crafted hand-axes manufactured at least 400,000 years ago, which were a great advance on earlier pebble choppers. Flint knapping involves many steps, and has to be paused and resumed many times. This implies a level of comprehension – a sustained idea of the purpose of the tool by the individual making it – that would not be evident in the non-human examples I’ve given. The use of fire by kites and falcons to flush out prey is impressive, but it’s a far cry from a careful tending of the flame in anticipation of its future use, and an even further cry from the employment of fire in smelting, making pots, or cooking. No need to eat your heart out, Prometheus: the avian fire-tamers do not have even elementary pyrotechnics.
Secondly, many human tools are employed to work in conjunction with other tools, for a variety of purposes (including the manufacture of tools). Often, the tools are put together out of components, which may well be manufactured separately: consider the wooden handle and metal head of a hammer. A tool may even be part of a suite of tools, such as a set of ratchets and screwdrivers. Individual tools also frequently form part of a composite – for example, wheel plus tyre plus chassis etc to make a car. And such composite, higher-order tool use has no obvious limit. Screws are made in order to assemble, and hold together, other tools. Spanners and screw-drivers are manufactured to screw screws. Machines are created to produce spanners and screw-drivers. Other devices are invented to monitor and regulate the machines making the spanners. There is no apparent terminus to this chain of connected tool-borne purposes, and there is much traffic up and down between parts and wholes. And then there are those autonomous tools that we call machines, incorporating thousands of patented ingenuities, and often able to operate for long periods of time in the absence of human intervention or direction. There is nothing at all like this in the rest of the animal kingdom.
Thirdly, many components of tools are used in a variety of circumstances which have little in common with one another. An obvious example is the wheel; another, no less impressive, is the cog, which finds itself in a variety of places, discharging a multitude of tasks.
Fourthly, getting ‘tooled up’ in animals is overwhelmingly (though not entirely) about the local, specific, here-and-now needs of the individual organism or small groups of organisms. This is in sharp contrast to the tool shop of the human community and the ‘artefactscape’ of the human habitat, where implements are held in common for an invisible future structured by shared mental time travel not observed in animals, orchestrated by clock and calendrical time. We keep stores of our part-tools and tool parts, and even of the items that keep composite items together – screws, glues, threads. There’s nothing in animal life comparable to the assembling of the ingredients or components of tools gathered or manufactured at different times being held in stock until they’re needed. Admittedly, some tool-using animals, such as Caledonian crows, keep their tools in case they are needed. They are not, however, housed in a common store for use by authorised individuals at some indefinite future time.
Fifthly, and perhaps most tellingly, there has been little evolution of animal tool use. Several million years ago, it is reasonable to assume, both hominins and non-human primates were level-pegging, using sticks or stones to crack open fruit. This was their cutting-edge technology. Several million years later, human cutting-edge technology includes nuclear power stations and mobile phones, while chimpanzee cutting-edge technology involves, well, using sticks or stones to crack open fruit.
Sixthly, the opportunistic, localised use of proto-tools seen widely in the animal kingdom does not join up into an all-purpose sense of the possibility of manipulating the world. It does not draw on, and bring together, insights from previously remote areas of concern. Yet we can see this happening in humanity in something quite simple, such as assisted portability, expressed through a thousand enhancements of the grasp, from containers and trays to the myriad manifestations of wheeled carriers, such as horse-drawn carts, trains, and planes, and the infrastructure that supports them. Animals do not generalise the principles implicit in one tool to the possibility of another more powerful. They don’t realise how tool creation can be principle-led, with, for example, the use of levers giving rise to a theory of levers driving ever-more-complex higher-order lever-based technology.
Finally, the increasing complexity of tools and the skills needed to use them is reflected in a division of labour underpinned by the distribution of different kinds of knowledge, skill, and expertise between trained individuals, who are allocated different roles in the collective endeavour to meet our needs.
In short, the soubriquet Homo faber (‘man the maker’), designating the creature uniquely shaping its destiny, and its routes to its destiny, through tools, is well-earned.
What the human hand has made
Night city © Garybhaztara 2017
Making A Difference
Behind all these developments is a vast cognitive hinterland. At its heart is the uniquely joined or collective intentionality of human consciousness. Our shared attention weaves the dense cognitive fabric of the human world into a common body of factual knowledge and belief which makes possible a collectively acknowledged reality we can address, interrogate, and act upon using our summed intelligence. It is this realm that we populate with millions of artefacts and the infrastructure in which they are used: buildings, highways, institutions. The most spectacular, albeit relatively recent, expression of this public realm, is the city – a vast, interconnected, interdigitated, multiplicity of systems of technologies, whose use is chaperoned by rules and regulations, permissions and vetoes.
Among the faculties explaining the gulf between other tool-using animals and Homo faber is a sense of direct and indirect causation, both as an intrinsic feature of the natural world and as a handle with which the world can be manipulated. Nothing in the fragmentary, episodic, opportunistic tool use by animals comes anywhere near to joining up into a general sense of the possibility of manipulating their world guided by general principles and shared knowledge.
Any investigation of the extraordinary nature of human tool use will have to dig deep into how we came to be cognitively so different. But we must first acknowledge the scale of what is to be explained, and see the full glory of Homo faber. I hope I have unpeeled your gaze.
© Prof. Raymond Tallis 2019
Raymond Tallis’s book, Logos: The Mystery of How We Make Sense of the World, has recently been published by Agenda.