Alva Noë is a professor of philosophy at the University of California and author of Out of Our Heads: Why You Are Not Your Brain, and Other Lessons From the Biology of Consciousness (Hill and Wang, $25).   –Christine Smallwood

I use the word "consciousness" in a narrow sense and in a broader sense. In the narrow sense I mean the experience of seeing something, or hearing something, or having a feeling. In the broader sense I just mean the whole colorful life of the mind: our thoughts, our feelings, our hopes, the desires that shape the contours of our lives. I don’t think of consciousness as something that happens in us or to us but as something that we achieve or something that we do through our action and interaction with the world around us. Why do many scientists see consciousness as the dynamics of brains meeting worlds?

I can give a simple answer. There is a certain kind of cultural ideology that stems from the great philosophers of the early modern period, especially Descartes, and perhaps also resonates with certain religious traditions, according to which inside each of us there is a thinking thing, a locus of consciousness. Is that thinking thing inside us immaterial–is it soul-stuff? Or is it something material–is it the brain? That’s the metaphor that ideologically shapes the picture.

One place where I think there’s source for concern is with the so-called brain-imaging technologies such as MRI or PET scans. Scientists have the idea that these technologies are photographing or depicting the brain in action or catching the brain in action as it thinks, as it feels, as it acts. In fact, those technologies are highly theoretically laden ways of thinking and talking about what’s going on in the brain. There are many layers of interpretation and supposition. We assume that the cognitive phenomena are neural events, and we assume that the neural events correspond to metabolic processes, and we assume that the physical magnitudes we’re measuring correspond to the metabolic processes. There’s a sense in which these brain images are more like composite police sketches than photographs. Does your work on consciousness have consequences for interspecies relationships, for animal rights?

The classical picture of our human predicament is that we’re all interiority and the world as far as we know is nothing but a source of impingement. We’re bombarded with sensory stimulation, and insofar as we think we occupy a world with an independent existence and other people, all that is really sort of conjecture; we’re trapped inside the caverns of our one conscious mind. I’m offering a different picture, where the world and the others around us come first, and we are spread out and plugged in and implicated. Think of a row of bushes: each bush is interwoven with the other bushes, the roots reach down into the ground and entangle with each other. The picture that emerges is we’re at home in the world, we’re of the world, the world is not a projection or this alien thing, just as other people are not just merely acting bodies but are present for us as meaningful and important. The natural extension of that is to acknowledge that the species boundary is not a particularly special boundary. When you encounter life, especially animal life but not only animal life, you don’t hypothesize the presence of the life around us. That there’s life around us and that we get it and we recognize it is the precondition for the kind of life that we are. So we’re not just brains in vats.

Exactly. I argue that our commitment to the minds of others isn’t, strictly speaking, a theoretical one; it’s more like a moral or existential one. It’s a condition of the kinds of relationships we enjoy with them. I couldn’t love you if I thought of you as a hypothetical explanation of the sensory experiences I have when I look at you. What that seems to mean as a consequence is that it isn’t possible to recognize mind in the universe from a purely disengaged, detached, objective, theoretical standpoint. And that seems to have the consequence that we can’t really have a science of the mind, because science requires that you take a detached, objective attitude toward things. We don’t have to accept that consequence, but we need to realize that there is a kind of natural scientific perspective on mind that is not detached, and I call that the biological perspective. Exactly the same things can be said about life. When I recognize a little bacterium as living, I’m thinking of it as not merely a locus of chemical processes; I’m thinking of it as doing things, having interests, seeking food, preserving its unity in the fluid that it’s floating around in and not just dissolving. I’m singling it out as having a story, as having an identity. And you can’t do that unless in some sense you already take life in a kind of primitive way for granted. We need to enrich our conception of what our so-called scientific study of these phenomena is if we really want to understand them. What are the consequences of that?

We do not yet have an explanation of life, if by that we mean an understanding of how the merely chemical, the merely inorganic, put together in the right way produces life. It’s true that, given that the chemicals are put together in the right way and you get proteins, you can tell the whole evolutionary story. But nobody knows how to make life in a test tube. And we need to recognize that. I’m trying to make a similar point about mind, but with this addition: yes, it’s true that we can’t explain minds just in terms of neural processes, but why should we? Consciousness doesn’t happen inside us. You’re looking for consciousness in the wrong place. Similarly, life doesn’t happen inside the animal alone. Life is, like mind, something that is achieved in this sort of larger dynamic of interaction.