The tacit nature of craft results in one of the curious inversions that marks its invention: it was precisely the wide publication of technical secrets that yielded the insight that artisanal skill is fundamentally incommensurable with discourse. Like a conjurer’s trick, even when seen up close, craft process doesn’t reveal itself entirely, nor can it easily be repeated. So one counterintuitive message of the nineteenth-century technical manuals, for all their expansive detail, is that to really teach a given process requires repeated demonstration, and then (crucially) handing over the tools. The only way to really learn a craft is to do it yourself, over and over; not only reading about it, but even seeing it enacted at close range is a mere spectator sport.
This was another idea about craft that was forged in the period of the industrial revolution: though it could be described, it could never be fully accounted for in words. Nor is it universally consistent. According to the terms of its modern invention, craft does not involve knowledge that can be set down, but this is always a matter of incomplete approximation, because artisanal skill is personal, intuitive, and capricious (in the sense that its results will be different in each set of hands, and from one piece of raw material to another). You can put craft knowledge in a book, but it will still be tricky to put it into practice. Within this modern framework, craft is opposed to other, more explicit and objective categories of knowledge: science and engineering. This division is itself a cultural artifact, but so powerfully have our own intuitions about craft been shaped by the modern idea that it is nonverbal and intuitive that we cannot imagine any other way of seeing it. Yet this understanding of practical know-how had certainly not been prevalent prior to the eighteenth century–prior to the differentiation of craft from other ways of making and knowing. Within the early modern field of production–that is, from the Renaissance up until the eighteenth century–tacit and explicit knowledge were not distinguished from one another.
Glenn Adamson, The Invention of Craft