From “Where Is Everybody?” by Jim Al-Khalili:
“Of course, an alien planet being suitable for life is one thing, but the really big unknown is this: given the right conditions, how likely is it that life could evolve elsewhere? To answer is that we need to understand how life began on Earth. If we are indeed alone in the vastness of the cosmos, then we need to understand why we are so special. Why would the Universe be apparently so finely tuned for life to exist, yet harbour it in just one isolated corner?
One way of thinking about this is to ask yourself how come you exist? What were the chances that your parents would meet and produce you? Indeed, what were the chances of their parents meeting, and so on all the way back? We are each of us the culmination of a long and highly unlikely chain of events leading back to the origin of life itself. Break any one of the links in that chain and you would not be here to ask the question in the first place. Maybe our existence is really no more remarkable than the lottery winner contemplating his or her good fortune: had that sequence of numbers not come up, then someone else would have won and they would also reflect on the improbable odds of their win.
What life on Earth can tell us about alien existence elsewhere in the Galaxy is limited by the fact that we have a statistical sample of just one. Our own example tells us nothing about the likelihood of life elsewhere, or what it would look like if it did exist. Could there be advanced alien civilisations out there or would they only be in the form of simple, single-celled microbes? If we can’t begin to address that issue, how will we even know where to look?
Most profound of all of course is what it would mean for us if we did find them?”
From “What Are We Looking For?” by Nathalie Cabrol:
“At the crossroads of scientific disciplines, astrobiology uses advances in all fields to answer these questions: How does life begin and develop? Does life exist elsewhere in the Universe? What is life’s future on Earth and beyond?
These questions represent a puzzle of cosmic proportions, to which we are missing several key pieces. We do not have a clear definition of what life is. Could it have been seeded on Earth through panspermia (in which comets and asteroids transfer material between other bodies in the solar system on impact) and planetary exchange (the idea, for example, that there was some exchange of material between Mars and Earth at the time they were forming)? Or was it created on our planet through abiogenesis, a process by which life arises naturally from simple organic compounds and chemical processes? We also do not have a record of when – or in which environment – the transition from prebiotic chemistry to life took place. We don’t know whether life is a common universal occurrence or a fluke. But if we are to solve the puzzle, it makes sense to start with us.
The terrestrial biosphere we inhabit – even if it hasn’t provided the answers to the questions above – is a record of life’s evolution and adaptation driven by environmental and cosmic bottlenecks, extending over billions of years. Further away, we can see the solar system we belong to as a lab where, over eons, nature has created a diversity of environments surpassing in complexity anything we could develop in an experiment. Beyond the solar system, our most sophisticated instruments provide windows in space and time where we can catch a glimpse of how galaxies, stars and planets are formed. Last, but not least, the human mind can model, theorise, and generate limitless thought experiments.
With this in hand, we have started to build an understanding of what, where and how to search for life beyond our planet. By necessity, our vision is still anthropocentric: we are searching for life as we know it, and this approach is a logical one because it is always easier to start with what you know, when what we know of life is still so limited. As our knowledge broadens, hypotheses and models grow more complex, and the technology to test them becomes more sophisticated, which allows more discoveries to be made, and fundamental hypotheses and models to be refined. This is an iterative process. In that regard, the past few decades of exploration of the Earth’s most extreme environments, the solar system, and deep space have revolutionised our definition of habitability and life potential.”
From “It Came From Beyond The Silver Screen!” by Adam Rutherford:
They mostly get it wrong. Mostly. Film-makers have been infusing culture with their visions of aliens for more than a century, and almost all of them have been a lot like us. The Moon natives in the first cinematic trip into space, Georges Méliès’s La Voyage dans la Lune (1902), were Selenites, named after Selene, the Greek goddess of the Moon. They’re a bit like arthropods with bulbous heads and lobster claws, but mostly human – upright and bipedal. The next trip was when the 1919 adaptation of H. G. Wells’s The First Men in the Moon landed, which also had Selenites as the endogenous lunar men. Alas, all prints of the film are lost. In the few remaining stills from the shoot, the Selenites are also somewhat insectoid, but look disturbingly like the blue, globoid-headed, oval-bodied Igglepiggle from the bewildering otherworldly toddlers’ programme In the Night Garden. And so the tone was set for a century of aliens – humanoid, insect or insect-like humans are the mainstay of cinematic extraterrestrials. We turn to human-like forms either because of budgetary constraints or for reasons of anthropocentrism.
We lazily assume aliens will be a bit like us, because we do like thinking about ourselves. Star Trek and dozens of imitators have got away with simply gluing bits of lump onto human faces or painting them green to indicate their non-human status. The Star Wars Universe offers little but variations on humans. Budget didn’t seem to be much of a problem in James Cameron’s Avatar (2009), just a tiresome lack of imagination. ‘Let’s make them taller than us, and a bit cat-like, but sexy, and give them tails. They need to be primitive but wise. Oh, and make them blue too.’
We have a pretty good grasp of evolution these days, and our bounteous fossil record, now coupled with genetics, gives us a picture of how life evolved on Earth. There are plenty of mysteries remaining, but we know much about our nearest ancestors: the emergence of bipedalism and all the many factors by which we came to be who we are. To assume that on other worlds, evolution would deliver a species identical in physical stature is plain silly. We don’t really know why we became two-legged when almost all terrestrial animals are not, but we can hypothesise that it is an adaptation to a range of complex environmental conditions, primarily to equip a species for a life on the savanna rather than swinging in the trees, and an increased efficiency of movement. If the Earth ever got a reboot, and the story ran again from the beginning, with just a few variables altered we would not have come out like this. Even a seemingly unconnected matter like the tilt of the Earth’s axis has played a crucial role. That 23° tilt, which gives us our seasons, was caused by a rock the size of Mars colliding with the neonate Earth, and knocking off a block that would form the Moon. Imagine if the rock had missed; no tilt, no seasons, no Moon, no tides. This would have meant a different weather system, different climate changes over time, and an entirely different set of evolutionary ancestors. Imagine if that sixmile-wide asteroid hadn’t tumbled out of the Cretaceous sky into what is now the Gulf of Mexico and caused an extinction level event that wiped out the dinosaurs and so many other species, yet allowed our small mammal ancestors to thrive. Imagine that rock being half the size, and only half of the dinosaurs had been wiped out. Would we be as we are? The answer is almost certainly no. Our form is not inevitable – it’s mere cosmic happenstance.”
‘Know thyself’ is one of philosophy’s most ancient aphorisms. But is there such a thing as the self and, if there is, can it be empirically investigated through scientific methods? Antirealists deny the existence of the self – for them it is an illusion, a fiction of the mind. If there was no one to perceive it, there would not be a self. The concept of the self, in their telling, is invented by cultural, social and linguistic conventions. It is nothing but a useful conceptual tool for organising human experience.
David Hume, the 18th-century Scottish philosopher and economist, remains the preeminent antirealist. He suggests that we have no experience of a simple, individual impression that we can call the self – where the ‘self’ is the totality of a person’s conscious life. In A Treatise ofHuman Nature (1740), Hume wrote:
When I enter most intimately into what I call myself, I always stumble on some particular perception or other, of heat or cold, light or shade, love or hatred, pain or pleasure. I never can catch myself at any time without a perception, and never can observe anything but the perception.
Today, Daniel Dennett, a philosopher of mind and cognitive scientist at Tufts University in Massachusetts, also defends the antirealist view. For Dennett, each ‘normal’ individual of the species Homo sapiens creates a self by spinning stories about herself in the process of presenting herself to others through language. The tendency to create selves by way of creating stories, for humans, is akin to how spiders weave webs to protect themselves: it is both intrinsic and unconscious, argued Dennett in Consciousness Explained (1991). Because the self is constructed and abstracted out of narratives, it is permeable and flexible, and because of its permeability and flexibility, the self eludes scientific scrutiny.
The antirealists also argue that the phenomenal experience of the self requires ‘privileged access’, whereby the subject is a witness to her own mental states, and these mental states are not intersubjectively validated. For instance, how a teenager conceives of her body (say, as overweight) is given directly only to her, not to others. Perhaps she falsely represents herself to herself as overweight, due to cultural influences on her conception of what the ideal weight is. The self, then, according to the philosopher David Jopling at York University in Ontario, is experienced in ways that are intimately interlaced into the fabric of culture and language, so variations in culture and language will lead to different experiences of the self, making the self a non-stable, moving target, escaping scientific enquiry.
Or take individuals with schizophrenia, some of whom report a deep sense of disintegration between themselves and their actions. They feel that they are automatons, not agents who see, feel, eat, suffer – their bodies can feel to them like alien objects. Meanwhile, phenomenologically typical individuals are immediately aware that they are the subject of their feelings or actions, as they are simultaneously aware of said feelings. For them, the self is the ‘unarticulated constituent’ of experience, in the words of the philosopher John Perry of Stanford University in California. If science aims to come up with generalisable explanations and predictions of human behaviour, how can it empirically track a self that appears to be intrinsically flexible, private, subjective and accessible only to the subject whose self is in question?
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The answer is that science does all this by rejecting antirealism. In fact, the self does exist. The phenomenal experience of having a self, the feelings of pain and of pleasure, of control, intentionality and agency, of self-governance, of acting according to one’s beliefs and desires, the sense of engaging with the physical world and the social world – all this offers evidence of the existence of the self. Furthermore, empirical research in the mind sciences provides robust reasons to deny antirealism. The self lends itself to scientific explanations and generalisations, and such scientific information can be used to understand disorders of the self, such as depression and schizophrenia, and to develop this self-understanding facilitates one’s ability to live a rich moral life.
I call my proposed model the ‘multitudinous self’. ‘Do I contradict myself?’ asks the poet Walt Whitman in ‘Song of Myself’ (1891-92), ‘Very well then I contradict myself, / (I am large, I contain multitudes.)’ The multitudinous self is empirically tractable and responsive to the experiences of ‘real people’ who do or do not have mental disorders. According to this model, the self is a dynamic, complex, relational and multi-aspectual mechanism of capacities, processes, states and traits that support a degree of agency. The multitudinous self has five distinct but functionally complementary dimensions: ecological, intersubjective, conceptual, private, and temporally extended. These dimensions work together to connect the individual to her body, her social world, her psychological world, and her environment.
The multitudinous self is based on the psychologist Ulric Neisser’s account of the self, laid out in his paper ‘Five Kinds of Self-knowledge’ (1988). Neisser encourages us to reevaluate the sources of information that help us to identify the self. There are five sources, which are so different from one another that it is plausible to conceive each as establishing a different ‘self’. First there is the ecological self, or the embodied self in the physical world, which perceives and interacts with the physical environment; the interpersonal self, or the self embedded in the social world, which constitutes and is constituted by intersubjective relationships with others; the temporally extended self, or the self in time, which is grounded in memories of the past and anticipation of the future; the private self which is exposed to experiences available only to the first person and not to others; and finally the conceptual self, which (accurately or falsely) represents the self to the self by drawing on the properties or characteristics of not only the person but also the social and cultural context to which she belongs.
The multitudinous self is a variation of the Neisserian self in that it individuates the self as a complex mechanism with many dimensions that interact and work together to maintain a more or less stable agency over time. At times these different dimensions of the self contradict each other (very well then). Interpersonally, I might come across as gregarious, and present an image of a someone who enjoys companionship, yet my private sense of self might be that I am shy and introverted. Because these five dimensions are all more or less integrated, however, they help with self-regulation, and function as a locus of experience and agency. The multitudinous self gives a partial but helpful representation of the selves we encounter in our daily lives. It is also scientifically scrutable.
To see how this is so, take the following example. We can acquire information about the selfhood of 12-year-olds, tracking information about them in all five dimensions by relying on both first-person and third-person perspectives. First, we could interview them on how the physical changes in their bodies are manifested in their ecological dimension: how the changes in their height or weight affect their physical activity, or how such physical changes affect their interpersonal dimension through their effects on the nature and quality of their interpersonal relationships.
A girl’s weight might be typical for her height, sex and age, but not seem so to herself
Similarly, we can acquire information on how the physiological changes are manifested in the temporal, private and conceptual aspects of themselves. For instance, through first-person reports, we can evaluate whether and what kind of short-term memory loss the preteen might be experiencing, and whether it affects his sense of the future. This would yield information about the temporal dimension of the preteen self. Or we might learn about the private aspect of the self by interviewing them about ‘what it is like’ to be 12.
Finally, to develop a robust understanding of how their self-concepts are evolving in response to the changes they are undergoing, we might ask them how they represent themselves to themselves. Some might be changing their physical self-concepts – they might consider themselves tall after a radical growth spurt, or might think of themselves as overweight. Note that these alterations in self-concepts are not necessarily accurate or truth-tracking: a girl’s (or boy’s) weight might be considered in a typical range for her height, sex and age, but not seem so to herself.
The self of the preteen is also empirically tractable from a third-person perspective through sciences of the mind, including cognitive psychology, social psychology, clinical psychology, psychiatry, neuroscience and genetics. Through physiology and biology, we can determine the statistically typical range of changes in preteens’ bodies for their sex- and age-groups. We can evaluate the changes in their interpersonal dimensions, such as increased conflict with parents, by referring to research in developmental psychology, neuropsychology and social psychology. Similarly, we can acquire information about short-term memory loss and how it shapes temporality. Changes in the private dimension of the self can be at least partially tracked by analysing how behaviour changes. And alterations in the preteens’ conceptual dimension can be tracked through psychology and anthropology. For example, children in the United States tend to experience a decline in their positive self-concepts during their adolescent years; this decline often begins around age 12 for girls. Based on these first- and third-person perspectives, then, we can indeed draw reliable inferences about preteen selves.
Recall that the antirealists argue that the self is flexible, private, subjective and accessible only to the subject, which precludes the self from being the subject of sciences. The multitudinous-self model is responsive to this challenge as well. The flexibility, subjectivity and transiency of the self that antirealists have in mind are the features of the private and conceptual dimensions of the self – but this is not the whole complex mechanism of the self; there are other dimensions. The ecological dimension of the self (the body) is more or less stable and intersubjectively certifiable, readily lending itself to scientific scrutiny. The interpersonal dimension of the self can also be scrutinised by science; we can track a person’s family, relationships and socio-economic status through scientific research. So the temporal dimension of the self is also amenable to scientific investigation; whether a person has experienced a significant loss during childhood or whether his experience of trauma has affected his actions and self-related feelings can both be studied. The subjective and transient aspects of the self that antirealists delineate are actually the private and conceptual dimensions of the self. Recall the above example of people with schizophrenia: their private experiences of themselves reveal a disintegration of the sense of self; they feel as though they are the objects, not the subjects of their actions. In contrast, a person with a standard phenomenology might have a more robust and integrated sense of agency.
While antirealists are right to note the variability in self-concepts and private experiences of the self, this doesn’t mean that there aren’t regularities within the variability. We might, for instance, be able to find similarities in the private aspect of the self among those with schizophrenia, and use them to further our understanding of the illness, with the goal of helping those suffering from this condition. Similarly, the variability in self-concepts (eg, preteens and body-image issues) is an indication that self-concepts emerge from the interaction between the different dimensions of the self and the social and cultural world within which the person is situated. Scientists might find that those with supportive and positive interpersonal relationships, say, are less likely to develop negative self-concepts about their bodies.
Realism is mostly popular among psychologists and empirically informed philosophers of mind, such as William James in the late 19th century and, more recently, the aforementioned Jopling, as well as Owen Flanagan at Duke University in North Carolina and George Graham at Georgia State University. The reason for the realist commitment appears to be pragmatic. The reality of the self matters. The concept can be employed and manipulated in making sense of the complex human psyche, and successfully edifying enough so that the self is open to the enrichment of moral possibilities. For instance, in The Principles of Psychology (1890), James argued that a person’s self is
the sum total of all that he CAN call his, not only his body and his psychic powers, but his clothes and his house, his wife and children, his ancestors and friends, his reputation and works, his lands and horses, and yacht and bank-account. All these things give him the same emotions. If they wax and prosper, he feels triumphant; if they dwindle and die away, he feels cast down.
James’s postulation of the self not only tracks what the ordinary people whom we encounter in our daily lives are like, but is also helpful, for instance, to a clinician aiding a grieving patient, by helping that person to find ways of coping with loss.
The multitudinous-self model takes this pragmatism a step further: it is designed as a useful conceptual and empirical tool to expand scientific knowledge on mental disorders. Mental disorders do not influence or change exclusively one dimension of the individual – their interpersonal relationships, say – but multiple aspects of their lives simultaneously. Studying only one fractured aspect of their self (eg, autobiographical memory) will not yield the rich results that will come from engaging with the self in its complexity.
An integrated understanding of the different parts of the self is necessary to fathom the complexity of mental disorders
Take addiction. The addict has a physical dependency that prevents him from living a fulfilling life, but that is not where the story of addiction ends. The quality of an individual’s social relationships diminishes; he loses self-respect because his performance in his job declines; his self-concepts dramatically change as he now considers himself to be unreliable as opposed to trustworthy, and so on.
Because the multitudinous-self model tracks all the different dimensions of selfhood, it offers rich scientific resources to investigate and intervene on different aspects of mental disorders. It encourages the development of research programmes not only in neuroscience and genetics but also disciplines that study the role of interpersonal relationships, environment, culture and the epidemiological factors in the development of illness. While a fractured engagement with different parts of the self is important, there is virtue in maintaining the self as a research construct in its full complexity, because what happens in one component of the self affects the self as a whole. An integrated understanding of the different parts of the self is necessary to fathom the complexity of mental disorders.
The subjective and private dimensions that antirealists take to be obstacles to scientifically investigating the self do not pose a problem for the complex multilayered mechanism that I call the multitudinous self. And the variability in the private and the conceptual dimensions of the self can track some regularities and yield important information about, say, psychopathology, or how different social and cultural environments might create certain kinds of self-experiences and self-concepts.
The multitudinous self mediates scientific explanations of the complexity of real people with and without mental disorders. It also provides resources for enhancing the moral agency that permits people to flourish. For me, flourishing is simply the development of a person’s psychological and social skills in engagement with herself and with others, in the face of the challenges triggered by her physical, social and psychological environment. If we know the characteristics of the self, we might be able to improve the lives of those whose self-experiences are not conducive to flourishing. The self is not an idle concept, either scientifically or ethically; it organises human experience and proliferates moral possibilities. So, yes, know thyself. Every single part.
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is an assistant professor of philosophy and the director of the medical humanities minor at the department of philosophy and religious studies at Daemen College in Buffalo, New York. She is also an associate fellow at the Center for Philosophy of Science at the University of Pittsburgh. She is the co-editor, with Jeffrey Poland, of Extraordinary Science and Psychiatry: Responses to the Crisis in Mental Health Research (2017).