This work attempts to present the most important contributions of Humberto R. Maturana to the field of psychology, in an effort to reveal them directly. The main conclusion is that Maturana has expanded the understanding of humanness and therapy through revealing the biology of the observer.

Humberto Maturana’s concept of conversation as the braiding of emotion and language has been the basis of the authors’ framework-for-action, proving its usefulness across a number of research and consulting initiatives. We agree with Maturana’s claim that learning and change take place in a relational space, over time, and as a consequence of engagements shaped by the participants’ emotions. This paper is a tribute to the joy, and at times the frustration, that both authors have experienced from an ongoing conversation with Maturana’s work and our desire, wherever possible, to put it to the test. The paper will refer to research that illustrates the researcher as chorographer (one practiced in the systematic description of regions) and as choreographer (one practiced in the design of dance arrangements) of the emotions.

Latencies of the different types of ganglion cell responses to stimulation within a receptive field were measured in guinea pigs. The latency of the response evoked by stimulation of the center or intermediate zone was always less than the response evoked by stimulation of the periphery or intermediate zone. The on-off response had latency values as if the responses were independently elicited in the center and periphery. When two light spots were shone in the receptive field at different time intervals, it was found that one could cancel the other if shone in a precise time which was dependent on the latencies of the responses of the receptive field. To account for the observations, it is postulated that the time courses of excitation and inhibition can vary from ganglion cell to ganglion cell.

Machines and Biology have been, since antiquity, closely related. From the zoological figures present in astronomical simulacra, through renaissance mechanical imitations of animals, through Decartes’ wind pipe nerves, to present day discussions on the computer and the brain, runs a continuous thread. In fact, the very name of mechanism for an attitude of inquiry throughout the history of Biology reveals this at a philosophical level ([4] and [6]). More often than not, mechanism is mentioned in opposition to vitalism, as an assertion of the validity of the objectivity principle in biology: there are no purposes in animal nature; its apparent purposefulness is similar to the purposefulness of machines. Yet, the fact that one picks machines as a set of objects comparable to living systems, deserves a closer look. What in machines makes it possible to establish such a connection?

Context: Maturana’s published corpus is vast, and his publications span multiple venues, formats, and languages. For these and other reasons, the corpus is as complex as it is daunting in its scale. Problem: Over the last two decades, bibliographic data on Maturana’s publications had proliferated in terms of available resources, scope of coverage, and accessibility. However, as of 2011 the degree of accessibility was not matched by the inclusiveness, detail, and accuracy of the relatively few dedicated bibliographies upon which most such resources relied. It had become time to update, consolidate, and better validate the core bibliographic data. Method: The five most comprehensive electronic bibliographies were merged and collated. The merged listing was then validated using the available evidence and a three-tiered set of evaluation criteria. Finally, the resultant merged and validated listing was augmented with previously unrecorded entries and data, subject to the same evidentiary constraints and evaluation criteria pertaining to the validation phase. Results: None of the five bibliographies in the starting set was comprehensive. All five contained ambiguities, missing details, discrepancies, and outright errors. The updated and consolidated listing presented here is the largest, most comprehensive, and most accurate compiled to date. Implications: The resultant bibliography offers a more complete and more reliable reference resource to both veteran Maturana scholars and newcomers to his work than previously existing bibliographies.

Key words: Humberto Maturana, biology of cognition, autopoiesis, bibliography, publications