Abstract: What is it like to be a bat? This is one of the most famous questions ever asked in the history of consciousness studies. First posed in 1950 it was made famous in a 1974 paper of that name by American philosopher Thomas Nagel. Nagel argued that understanding how mental states can be neurons firing inside the brain is a problem quite unlike understanding how water canbe H2O, or how genes can be DNA. ‘Consciousness is what makes the mind-body problem really intractable,’ he said (Nagel, 1974: 435; 1979:165), and by consciousness he meant subjectivity. To make this clear he asked ‘What is it like to be a bat?’. Do you think that your cat is conscious? Or the birds outside in the street? Perhaps you believe that horses are conscious but not worms, or living creatures but not stones. We shall return to these questions (Chapter 12) but here let’s consider what it means to say that another creature is conscious. If you say that the stone is not conscious you probably mean that it has no inner life and no point of view; that there is nothing it is like to be the stone. If you believe that the neighbour’s vicious bloodhound, or the beggar you passed inthe subway, is conscious, then you probably mean that they do have a point of view; there is something it is like to be them. As Nagel put it, when we say that another organism is conscious we mean that ‘there is something it is like to be that organism . . . something it is like for the organism’ (1974: 436); ‘the essence of the belief that bats have experience is that there is something that it is like to be a bat’ (ibid.: 438). This is probably the closest we can come to a definition of consciousness – that consciousness is subjectivity, or ‘what it is like to be . . .’. Here we must be careful with the phrase ‘what it is like . . .’. Unfortunately there are at least two meanings in English. We might say ‘this ice cream tastes like rubber’ or ‘lying on a beach in the sun is like heaven’. In this case we are comparing things, making analogies, or saying what they resemble. This is not what Nagel meant. The other meaning is found in such questions as: What is it like to work at McDonald’s? What is it like to be able to improvise fugues at the keyboard?…to be someone inconceivably more intelligent than yourself?…to be a molecule, a microbe, a mosquito, an ant, or an ant colony? (Hofstadter and Dennett, (1981: 404-5), pose many more such provocative questions.) In other words, what is it like from the inside? Now, imagine being a bat. A bat’s experience must be very different from that of a human. For a start the bat’s sensory systems are quite different, which is why Nagel chose the bat for his famous question. Bats’ brains, lives and sensesare well understood (Akins, 1993; Dawkins, 1986). Most use either sound or ultrasound for echolocation. That is, they detect objects by emitting rapid high-pitched clicks that bounce off any objects in the vicinity and then measuring the time taken for the echo to return. Natural selection has found ingenious solutions to the many interesting problems posed by echolocation. Some bats cruise around emitting clicks quite slowly so as not to waste energy, but then when they are homing in on prey or approaching a potential danger, they speed up. Many have mechanisms that protect their ears from the loud blastof each click and then open them to receive the faint echo. Some use the Doppler shift to work out their speed relative to prey or other objects. Others sort out the mixed-up echoes from different objects by emitting downward-swooping sounds. The echoes from distant objects take longer to come back and therefore sound higher than the echoes from nearer objects. In this way we can imagine that a whole bat world is built up in which higher sounds mean distant objects and lower sounds mean nearer objects. What would this be like? According to Oxford biologist Richard Dawkins (1986; see Profile, Chapter 10), it might be like seeing is for us. We humans do not know, or care, that colour is related to wavelength or that motion detection is carried out in the visual cortex. We just see the objects out there in depth and colour. Similarly the bat would just perceive the objects out there in depth, and perhaps even in some batty, sonar, version of colour. Living in this constructed world would be what it is like to be the bat. But can we ever know what it would really be like for the bat? As Nagel pointed out, the question is not answered by trying to imagine that you are a bat. This will not do. It is no good hanging upside down in a darkened room, making little clicks with your tongue and flapping your arms like wings. Perhaps if you could magically be transformed into a bat you would know. But even this won’t do. For if you were a bat, the bat in question would notbe an ordinary bat – what with having your memories and your interest inconsciousness. But if you became an ordinary bat then this bat would have no understanding of English, no ability to ask questions about consciousness, and could not tell us what it was like. So we cannot know what it is like to be a bat even if we believe that there is something it is like to be a bat. Nagel’s question clarifies the central meaning of the term ‘consciousness’. It is what the American philosopher Ned Block (1995) calls ‘phenomenal consciousness’ or phenomenality. He explains that ‘Phenomenal consciousness isexperience; what makes a state phenomenally conscious is that there is something ‘it is like’ to be in that state.’ He distinguishes this from ‘access consciousness’, which is ‘availability for use in reasoning and rationally guiding speech and action’ (Block, 1995: 227). We will return to this distinction (Chapter 18), and consider issues to do with availability, but ‘phenomenal consciousness’ is what this book is all about. So what is it like to be you now? Everything I have said so far implies that there is, uncontroversially, something it is like to be you now – that the problems only begin when you start asking about what it is like to be someone orsomething else. But is this right? A thoroughly sceptical approach would meanquestioning even this. I urge you to do this chapter’s ‘Practice’ and become a little more familiar with what it is like to be you.