Emergence is interpreted in a non-dualist framework of thought. No metaphysical distinction between the higher and basic levels of organization is supposed, but only a duality of modes of access. Moreover, these modes of access are not construed as mere ways of revealing intrinsic patterns of organization: They are supposed to be constitutive of them, in Kant’s sense. The emergent levels of organization, and the inter-level causations as well, are therefore neither illusory nor ontologically real: They are objective in the sense of transcendental epistemology. This neo-Kantian approach defuses several paradoxes associated with the concept of downward causation, and enables one to make good sense of it independently of any prejudice about the existence (or inexistence) of a hierarchy of levels of being.

Key words: emergence, inter-level relations, anti-foundationalism, transcendentalism, objectivity, anti-realism, quantum mechanics.

Context: In the past three decades, the work of Varela has had an enormous impact on current developments in contemporary science. Problem: Varela’s thought was extremely complex and multifaceted, and while some aspects – notably his contributions to the autopoietic theory of living and enactivist approach to cognition – have gained widespread acclaim, others have been ignored or watered down. Method: We identify three dimensions of Varela’s thought: (i) anti-realism of the “middle way”; (ii) anti-foundationalism of the circular/recursive onto-epistemology; and (iii) ethical/social implications of the circularity/recursivity. The discussion of these dimensions is followed by a concise overview of the individual target articles in this issue and the topics they cover. Finally, we discuss in what ways the articles extend and relate to Varela’s work. We do this by means of a concrete example: the relation between “enaction” and “enactivism. Results: We show that the ignoring-cum-watering-down process of Varela’s contributions to science is at least partly linked to the three dimensions of Varela’s thought. Based on our examination we also find that the more narrow research topics are always interrelated with broader philosophical reflection. Researching into ignored and watered-down aspects of Varela’s work enables us to not only gain fresh insights into Varela’s overall philosophy and rekindle interest in the topics and themes that have been brushed aside, but also cast a fresh light on those that are currently in full bloom. Implications: Reviving interest in Varela’s work in toto could lead to fruitful research and discussion in numerous scientific fields. To illustrate this idea, we delineate, tentatively, three domains – theoretical, empirical, and existential – where Varela’s contribution to philosophy and science could instigate prolific exchange of views. Constructivist content: All three dimensions of Varela’s philosophy have strong affinities with radical constructivist critique of realism and some of its epistemological and ethical implications.

Key words: Francisco Varela, anti-realism, anti-foundationalism, certainty, circularity, enaction, enactivism, ethics, reality, second-order science, self-reflexivity