At this stage in the development of the analysis of the thinking actor I would like to make a connection to the notion of incommensurability, as it is formulated by Thomas Kuhn, one of the founding fathers of Science and Technology Studies. When faced with 'interdisciplinary projects' that have the aim of creating new things or structures, the sharing of insights and the acknowledging of other people's situations, and especially other people's language and conceptual lexicon, becomes vital to achieve even the slightest success. Apart from the exchange of respect, trust and responsibility, there is also the issue that people use the same words but with different meanings in different disciplines. This is why I will explicitly address incommensurability, the fundamental not-sharing of an understanding, as an issue in collaboration between different actors. At the GHP and the 0+Ball the incommensurability between the different actors also demanded a great deal of attention, as I described in chapter 3 and 4. In 1962 Kuhn published his book 'The structure of Scientific Revolutions', in which he analysed the way scientific paradigms change, and the way scientific revolutions take place. In his ideas the notion of incommensurability was crucial. After his death in 1996 a book was published of his latest writings in which he reflects upon his 30-year practice of exploration. In his essay 'The road since structure' he elaborates again on the concept of incommensurability.

Incommensurability is one of the key concepts, according to Kuhn, which can help us to understand the development of science. It is one of the factors with which one can describe paradigm shifts. It also helps us to understand the implications of the process of increasing specialization that characterizes the development of science; new fields of research with new taxonomies evolve over time. This has happened to the present day. Kuhn refers to his own experience with the development of the life sciences; 20 years ago one department in one university started this field of research, and today one can find the subject in many universities with all kind of specializations, which also develop their own taxonomies. Specialization can also be recognized in the development of professional practices. Does this notion of incommensurability, which was developed to understand the development of science, also apply to the development of practices for the thinking actor? And how does it relate to contextual reflexivity?

Kuhn writes: "Incommensurability thus becomes a sort of untranslatability, localized to one or another area in which two lexical taxonomies differ. The differences which produce it are not any old differences, but ones that violate either the no-overlap condition, the kind-label condition, or else a restriction on hierarchical relations that I cannot spell out here. Violations of those sorts do not bar intercommunity understanding. Members of one community can acquire the taxonomy employed by members of another, as the historian does in learning to understand old texts. But the process which permits understanding produces bilinguals, not translators, and bilingualism has a cost, which will be particularly important to what follows. The bilingual must always remember within which community discourse is occurring. The use of one taxonomy to make statements to someone who uses the other places communication at risk." (Kuhn 2000, 93).

Do the writer of a book and the person operating the printing press share a taxonomy or can we speak of an incommensurability between two practices, which may jeopardize their communication? They share certain concepts and certain materials. Both work with letters, both need paper. Both are concerned with a good representation of letters, both have a notion of readers and the readers' capacities. Both the writer and the printer wish to make communication with the reader possible. Nevertheless, the processes that they undertake to accomplish their task are completely different. The very same words mean and refer to something completely different for the writer and the printer. The writer needs some paper, but for the printer it is one of his primary materials and he uses tons of it. The writer uses the paper in a personal way, the printer uses all kinds of paper and he does this in an industrial way. However, both of them love paper and they could have a good conversation about the qualities of paper, the varieties of weight in paper, the roughness or smoothness, the textures, the colours, the pricesÉThe writer will wax lyrical about the feeling you have when you touch the paper while you write, or how the paper helps you to formulate an inspiration. The writer will speak about how a certain paper reacts to a certain pen. The printer will speak about how certain papers react to certain inks, how easily they jam the press or not, how a certain paper will dry and the printer will include the binding possibilities in his judgment on paper as well. To the writer, letters are only interesting in as far as they form words, which make sentences that the writer can use to communicate his or her ideas. For the printer words do not matter, it is the physical quality of the letters and how they are perceived that concern him. To the printer the text has a size that facilitates an amount, a figure, which has to match the printing plates. Will it be 4 or 8 or 16 pages in one run?

For a community of writers the conversation about text will be very different than for a community of printers. Some of the same words are used, but a piece of white paper is something completely different for a writer than for a printer. Yet a book can not come about without their collaboration.

The taxonomies of the writer and the printer do not overlap because the acts that they refer to with the use of a word like 'paper' are very different. And also the variables (size, amount, time to print, time to write, price), which determine how an act with paper is performed, are very different for the writer and the printer. However, there is also no incommensurability between them when looking at their work from the perspective of their product, the book. I would conclude that there is incommensurability between the actor who writes and the actor who prints as regards the actions to be performed by them, and I would also conclude that there is no incommensurability between them when discussing the aggregate effect of their efforts on their collaboration and the quality of their work in the end product. When the writer and the printer have to collaborate in the production of a book, they have to be able to understand each other at some point.