In an informal introduction to tacit knowledge that starts with Polanyi’s slogan – that we know more than we can tell – Harry Collins says:
That we humans do much of what we do without following explicit rules is no more mysterious than my cat hunting without knowing rules about hunting or a tree growing without knowing rules about forming leaves. We only think it's mysterious if we think explicitness is the norm, but explicitness is a rare thing, restricted to humans, and used only now and again because it is often more efficient to allow causal, neural connections in the brain and body to execute an action with little (or, indeed, no) conscious calculation - after all, cats do pretty well this way. [Collins 2010b]
In his recent book length treatment of the subject, Tacit and Explicit Knowledge, he makes use of the same demystifying comparison.
In all the ways that do not involve the way we intentionally choose to do certain acts and not others, and the way we choose to carry out those acts, the human, per individual body and brain... is continuous with the animal and physical world. We are just like complicated cats, dogs, trees, and sieves... Sometimes we can do things better than cats, dogs, trees and sieves can do them, and sometimes worse. A sieve is generally better at sorting stones than a human (as a fridge is better at chilling water), a tree is certainly better at growing leaves, dogs are better at being affected by strings of smells, and cats are better at hunting small animals... That teaching humans to accomplish even mimeomorphic actions is a complicated business, involving personal contact, says nothing about the nature of the knowledge, per se. [Collins 2010a: 104-5]
So, although the transmission of tacit knowledge is difficult and capricious, as his earlier book Changing Order argued, there need be nothing mysterious about practical or somatic tacit knowledge itself. It is something, to a first approximation, we share with animals, trees and even machines.
Only to a first approximation, because Collins thinks that the ascription of tacit knowledge must stand in a contrast to explicit knowledge. Thus, where there is no possibility of ascribing explicit knowledge, tacit knowledge should not be ascribed either. Properly speaking, although human behaviour is ‘continuous’ with that of animals, trees and sieves, none of those have tacit knowledge [ibid: 78].
Collins does not, however, explain what marks the discontinuity in the action itself: what it is about humans, when they act like animals, that distinguishes their action from that of animals. That is, why does such animal action, though tacit, count as knowledge? Again, his account addresses the tacit status of tacit knowledge only at the cost of threatening its knowledge status.
In fact, although Collins approaches tacit knowledge, as Gascoigne and I do in our current book book, through a suitable contrast with what is explicit, he is not sensitive to the requirement to chart a kind of personal knowledge in Polanyi’s phrase: knowledge for someone. We can make this point by taking as a clue the three sentences from the informal summary of his view which immediately precede the quotation above.
In The Logic of Tacit Inference, Polanyi argues persuasively that humans do not know how they ride, but he also provides a formula: ‘In order to compensate for a given angle of imbalance α we must take a curve on the side of the imbalance, of which the radius (r) should be proportionate to the square of the velocity (v) over the imbalance r~v2/α.’ While no human can actually ride a bike using that formula, a robot, with much faster reactions, might. So that aspect of bike-riding is not quite so tacit after all. That we humans do much of what we do without following explicit rules is no more mysterious than my cat hunting...[Collins 2010b]
The suggestion is that where an action could be could be codified in a formula, that tends to undermine its tacit status. In the case of bike riding, the explicit formula is not, however, one that could be used by humans to guide their own riding, at least under normal gravitational conditions, because of human bodily or somatic limits. This idea is pursued at length in Tacit and Explicit Knowledge to suggest that there are different varieties of tacit knowledge corresponding to different impediments to the efficacy of an explicit statement.
The focus, however, is not on how something is known by an epistemic subject but rather on the nature of the task or practice and whether it could in principle be explicated by someone else. Hence having said that ‘[somatic tacit knowledge] is continuous with that possessed by animals and other living things’ he goes on to say that ‘in principle it is possible for it to be explicated, not by the animals and trees themselves (or the particular humans who embody it), but as the outcome of research done by human scientists’ [Collins 2010a: 85]. But if the focus is on the nature of the subject’s own (tacit) knowledge, its explication by others is beside the point.
This orientation is clear when he considers the ability to type. For skilled typists, conscious following of the rules they learnt when they first learnt to type slows them down. But this point ‘this seems to bear on nothing but the way humans work; it does not bear on the way knowledge works’ [ibid: 104]. By ‘knowledge’ he seems to mean roughly what is known not how it is known: the nature of the task or practice as this might be performed by someone or something else. (‘Roughly’, because how it is known – theoretically or practically, demonstratively or in context-independent terms – impacts on what is personally known.)
One clue to this is that he aims to shed light on human typists’ tacit knowledge by commenting that this task could be performed by a machine that could follow explicit rules. Such a comparison is only relevant if he is concerned not with the human typists’ knowledge but the nature of the task of typing in general. The assimilation of knowledge and task is clear:
The constraints on the methods available for efficient typing by humans [by contrast eg with machines] are somatic limits; they have everything to do with us and nothing to do with the task as a task – nothing to do with knowledge as knowledge. [ibid: 104]
This suggests that his focus is on the realm of reference, of what is being picked out in the world, which may sometimes be the content of knowledge, rather than how it is known, the way it is grasped, whether tacitly or explicitly, theoretically or practically. That a task might be accomplished using either explicit knowledge or tacit knowledge need not undermine its tacit status in any one particular case. So the inference from ‘task as task’ to ‘knowledge as knowledge’ in that last quote does not go through.
Because his underlying method of examining tacit knowledge works by contrasting it with what is explicit, but because this is sometimes taken to be a matter of explicating or explaining by, for example, ‘reproducing the effects of somatic tacit knowledge in machines and computers’ [ibid: 160] rather of focusing on the nature of the knowledge for the subject, Collins’ treatment downplays the issue of knowledge as it concentrates on what would ensure something had to be tacit.
Collins, H. (2010a) Tacit and Explicit Knowledge, Chicago: University of Chicago Press
Collins, H. (2010b) 'Tacit knowledge: you don't know how much you know' New Scientist 31st May
PS for more on Tacit and Explicit Knowledge see this.