For millennia people have wondered what makes the living different from the non-living. Beginning in the mid-1980s, artificial life has studied living systems using a synthetic approach: build life in order to understand it better, be it by means of software, hardware, or wetware. This review provides a summary of the advances that led to the development of artificial life, its current research topics, and open problems and opportunities. We classify artificial life research into 14 themes: origins of life, autonomy, self-organization, adaptation (including evolution, development, and learning), ecology, artificial societies, behavior, computational biology, artificial chemistries, information, living technology, art, and philosophy. Being interdisciplinary, artificial life seems to be losing its boundaries and merging with other fields. Relevance: Artificial life has contributed to philosophy of biology and of cognitive science, thus making it an important field related to constructivism.

This book asks the sciences of the mind to test their own boundaries, demanding that they account for a number of cognitive and experiential phenomena that are at the edge of the very possibility to cognize. We believe that this is a foundational challenge for the enactive approach to the mind, and, moreover, it is a challenge that – if actually won – might offer a persuasive theoretical framework even to those who have so far been skeptical about enactivism’s capacity to deal with higherlevel cognition.

The enactive approach replaces the classical computer metaphor of mind with emphasis on embodiment and social interaction as the sources of our goals and concerns. Researchers from a range of disciplines unite to address the challenge of how to account for the more uniquely human aspects of cognition, including the abstract and the nonsensical.

Is an individual agent constitutive of or constituted by its social interactions? This question is typically not asked in the cognitive sciences, so strong is the consensus that only individual agents have constitutive efficacy. In this article we challenge this methodological solipsism and argue that interindividual relations and social context do not simply arise from the behavior of individual agents, but themselves enable and shape the individual agents on which they depend. For this, we define the notion of autonomy as both a characteristic of individual agents and of social interaction processes. We then propose a number of ways in which interactional autonomy can influence individuals. Then we discuss recent work in modeling on the one hand and psychological investigations on the other that support and illustrate this claim. Finally, we discuss some implications for research on social and individual agency.

Key words: agency, autonomy, cognitive gap, coordination, modeling, participatory sense-making, perceptual crossing, social interaction, social cognition

This paper supports the view that the ongoing shift from orthodox to embodied-embedded cognitive science has been significantly influenced by the experimental results generated by AI research. Recently, there has also been a noticeable shift toward enactivism, a paradigm which radicalizes the embodiedembedded approach by placing autonomous agency and lived subjectivity at the heart of cognitive science. Some first steps toward a clarification of the relationship of AI to this further shift are outlined. It is concluded that the success of enactivism in establishing itself as a mainstream cognitive science research program will depend less on progress made in AI research and more on the development of a phenomenological pragmatics.

Key words: AI, cognitive science, paradigm shift, enactivism, phenomenology.

An important part of David Hume’s work is his attempt to put the natural sciences on a firmer foundation by introducing the scientific method into the study of human nature. This investigation resulted in a novel understanding of the mind, which in turn informed Hume’s critical evaluation of the scope and limits of the scientific method as such. However, while these latter reflections continue to influence today’s philosophy of science, his theory of mind is nowadays mainly of interest in terms of philosophical scholarship. This paper aims to show that, even though Hume’s recognition in the cognitive sciences has so far been limited, there is an opportunity to reevaluate his work in the context of more recent scientific developments. In particular, it is argued that we can gain a better understanding of his overall philosophy by tracing the ongoing establishment of the enactive approach. In return, this novel interpretation of Hume’s ‘science of man’ is used as the basis for a consideration of the current and future status of the cognitive sciences.

Key words: enactivism, hume, phenomenology, life, mind, enactive cognitive science, human nature.

Context: The enactive paradigm in the cognitive sciences is establishing itself as a strong and comprehensive alternative to the computationalist mainstream. However, its own particular historical roots have so far been largely ignored in the historical analyses of the cognitive sciences. Problem: In order to properly assess the enactive paradigm’s theoretical foundations in terms of their validity, novelty and potential future directions of development, it is essential for us to know more about the history of ideas that has led to the current state of affairs. Method: The meaning of the disappearance of the field of cybernetics and the rise of second-order cybernetics is analyzed by taking a closer look at the work of representative figures for each of the phases: Rosenblueth, Wiener and Bigelow for the early wave of cybernetics, Ashby for its culmination, and von Foerster for the development of the second-order approach. Results: It is argued that the disintegration of cybernetics eventually resulted in two distinct scientific traditions, one going from symbolic AI to modern cognitive science on the one hand, and the other leading from second-order cybernetics to the current enactive paradigm. Implications: We can now understand that the extent to which the cognitive sciences have neglected their cybernetic parent is precisely the extent to which cybernetics had already carried the tendencies that would later find fuller expression in second-order cybernetics.

Key words: W. Ross Ashby, Heinz von Foerster, constructivism, enactive cognitive science

In this article I take an unusual starting point from which to argue for a unified cognitive science, namely a position defined by what is sometimes called the “life-mind continuity thesis.” Accordingly, rather than taking a widely accepted starting point for granted and using it in order to propose answers to some well-defined questions, I must first establish that the idea of life-mind continuity can amount to a proper starting point at all. To begin with, I therefore assess the conceptual tools that are available to construct a theory of mind on this basis. By drawing on insights from a variety of disciplines, especially from a combination of existential phenomenology and organism-centered biology, I argue that mind can indeed be conceived as rooted in life, but only if we accept at the same time that social interaction plays a constitutive role in our cognitive capacities.

Varela is well known in the systems sciences for his work on second-order cybernetics, biology of cognition, and especially autopoietic theory. His concern during this period was to find an appropriate epistemological foundation for the self-reference inherent in life and mind. In his later years, Varela began to develop the so-called ‘enactive’ approach to cognitive science, which sets itself apart from other sciences by promoting a careful consideration of concrete experiential insights. His final efforts were thus dedicated to finding a pragmatic phenomenological foundation for life and mind. It is argued that Varela’s experiential turn – from epistemology to phenomenology – can be seen as a natural progression that builds on many ideas that were already implicit in second-order cybernetics and biology of cognition. It is also suggested that the rigorous study of conscious experience may enable us to refine our theories and systemic concepts of life, mind, and sociality.

Critics of the paradigm of enaction have long argued that enactive principles will be unable to account for the traditional domain of orthodox cognitive science, namely “higher-level” cognition and specifically human cognition. Moreover, even many of the paradigm’s “lower-level” insights into embodiment and situatedness appear to be amenable to a functionalist reinterpretation. In this review, I show on the basis of the recently published collection of papers, Enaction, that the paradigm of enaction has (a) a unique foundation in the notion of sense-making that places fundamental limits on the scope of functionalist appropriation; (b) a unique perspective on higher-level cognition that sets important new research directions without the need for the concept of mental representation; (c) a new concept of specifically human cognition in terms of second-order sense-making; and (d) a rich variety of approaches to explain the evolutionary, historical, and developmental origins of this sophisticated human ability. I also indicate how studies of the role of embodiment for abstract human cognition can strengthen their position by reconceiving their notion of embodiment in enactive terms.

Key words: cognitive science, enactive approach, higher-level cognition, representation, functionalism.