Francis Crick’s 1994 book ‘The Astonishing Hypothesis’ famously begins with the ‘nothing but a pack of neurons’ paragraph:
The Astonishing Hypothesis is that ‘You,’ your joys and your sorrows, your memories and your ambitions, your sense of personal identity and free will, are in fact no more than the behaviour of a vast assembly of nerve cells and their associated molecules. As Lewis Carroll’s Alice might have phrased it: “You’re nothing but a pack of neurons.” This hypothesis is so alien to the ideas of most people alive today that it can truly be called astonishing.
(Incidental note: he doesn’t actually say that you are nothing but a pack of neurons, as he puts the words in Alice’s mouth.)
Neuroscience has made reasonable progress in the last 20-ish years since the book’s publication so that it is generally better to now look elsewhere for more up-to-date accounts of the ‘amazing hypothesis’. But the book’s final chapter – ‘Dr Crick’s Sunday Morning Service’ is still fresh and so well worded after all these years.
Below are some quotes selected from that sermon of a chapter in the order they appear – with bold and underlining emphasis added by me, and some commentary on my part inserted, including tying Crick’s quotes in with my previous and future talks. Here goes…
Philosophers are right in trying to discover better ways of looking at the problem and in suggesting fallacies in our present thinking. That they have made so little progress is because they are looking at the system from outside.
Many philosophers and psychologists believe it is premature to think about neurons now. But just the contrary is the case. It is premature to try to describe how the brain works using just a black box approach, especially when it is couched in the language of common words.
One way of demarcating psychology and neuroscience is to say that psychology is ‘top-down’ whereas neuroscience is ‘bottom-up’. This is useful to some extent; psychology generally looks at whole-brain behaviour but has used information from pathology for example to isolate behavioural functions to parts of the brain (coarsely) whereas neuroscience includes building up behaviour from increasingly complex neural simulations. But neuroscience can also take large-scale view, such as using brain scans to make neural correlates, which is a more productive way to make progress than having to rely on pathology to report on the misfortunes of individuals. Brain-observing instruments such as EEG and MRI were originally used within the discipline of psychology but we now associate these with neuroscience now that psychology has given birth to that new science.
Progress in understanding complex system is often made by a combination of top-down and bottom-up approaches. This seems true with psychology and neuroscience, but I don’t see psychology making much ‘downwards’ progress, decomposing further. An alternative demarcation between the two sciences is of a ‘black box’ versus a physicalist approach:
- Psychology studies the brain as a ‘black box’, interpreting its behaviour without questioning how it actually works and what is inside it.
- Neuroscience studies the brain as it is physically (biologically) constituted.
Note in simplistic terms, psychology can be practiced by both dualists and physicalists whereas neuroscience really requires some commitment to physicalism.
Psycholical experiments can yield predictions but psychology can generally only describe brain behaviour – in ‘common words’. In contrast, neuroscience has the prospect of modelling behaviour in predictive simulations. And when we are able to make successful predictions, we can be confident that we have a good hypothesis. Only then can we summarize our understanding in ‘common words’. First comes the predictive modelling, then comes the popularizing descriptions.
I have said almost nothing about qualia – the redness of red – except to brush it to one side and hope for the best. In short, why is the Astonishing Hypothesis so astonishing? Is there some aspect of the brain’s … behaviour that might suggest why it is so difficult for people to conceive of awareness in neural terms? I think there is. I have described the general workings of an intricate machine – the brain – that handles an immense amount of information all at once, in one perceptual moment. … We have no experience (apart from the very limited view provided by our introspection) of any machine with all these properties so it is not surprising that the results of that introspection appear so odd…. If we could build machines that had these astonishing characteristics and could follow exactly how they worked, we might find it easier to grasp the workings of the human brain. The mysterious aspects of our consciousness might disappear, just as the mysterious aspects of embryology have largely disappeared now that we know the capabilities of DNA, RNA and protein. … Will we be able, in the future, to build such machines and, if we did, would they appear to possess consciousness? … Until we understand what makes us conscious, we are not likely to be able to design the right sort of artificial machine or to arrive at firm conclusions about consciousness in lower animals.
Philosophers have had such a poor record over the last two thousand years that they would do better to show a certain modesty rather than the lofty superiority that they usually display. … I hope that more philosophers will learn enough about the brain to suggest ideas about how it works, but they must also learn how to abandon their pet theories when scientific evidence goes against them or they will only expose themselves to ridicule.
Philosophers should not reject neuroscience, yet some philosophers almost seem to take pride in their ignorance of it.
In trying to discuss such an overwhelmingly complex object that the brain is in ‘common words’, philosophizing about consciousness becomes a non-productive activity – a ‘glasperlenspiel’ played in academic ivory towers, divorced from the real world (cf. Daniel Dennett’s ‘chmess’).
It is not productive to discuss vague notions such as qualia in ‘common words’. It is better to put this to one side and learn how to model (i.e. build) the brain such that it displays the correct externally-observable behaviour. It is so difficult for us to comprehend that machines (such as computers running these models) could be conscious. We are able to experiment with models in the way we can’t (ethically) with real brains. And it seems to me that these models should be able to provide substantially better reasons for our claims about animal consciousness that just arguments in ‘common words’.
Neither science nor philosophy should be practised exclusively but there tends to be a ‘time for science’ and a ‘time for philosophy’. As previous quoted:
Philosophers are right in trying to discover better ways of looking at the problem and in suggesting fallacies in our present thinking.
…but this is most useful when we are at a crisis point rather than when the scientific way ahead is clear. Neuroscience seems to be in a ‘normal science’ phase (to use Thomas Kuhn’s terminology) currently with large projects (such as the Human Brain Project) being undertaken. I am not saying that philosophy should be rejected but that now is not the time for philosophers to be ignoring neuroscience (just as scientists should be prepared to step outside of their normal work and philosophize during a ‘paradigm shift’ crisis).
It is unlikely that the Astonishing Hypothesis, if it turns out to be true, will be universally accepted unless it can be presented in such a way that it appeals to people’s imagination and satisfies their need for a coherent view of the world and themselves in terms they can easily understand. It is ironic that while science aims at exactly such a universal view, many people find much of our present scientific knowledge too inhuman and too difficult to understand.
Many people of a scientific persuasion find it hard to understand why so many others cling to a duallist worldview (such as Christianity) despite the ‘overwhelming scientific knowledge’. Now, dualism may be fundamentally flawed but, to be said in its defence, it does provide a remarkably coherent basis for a worldview. In contrast, physicalism is an incomplete worldview, still under construction (most significantly because it cannot currently provide a satisfactory account for consciousness in physical terms), and hence will not currently satisfy a large proportion of the population.
I will be discussing this more in the upcoming talk ‘What I Know and Why I Know It’.
While we may not be able to deduce human values solely from scientific facts, it is idle to pretend that scientific knowledge (or unscientific knowledge, for that matter) has no influence on how we form our values. To construct a New System of the World we need both inspiration and imagination, but imagination building on flawed foundations will, in the long run, fail to satisfy. Dream as we may, reality knocks relentlessly at the door. Even if perceived reality is largely a construct of our brains, it has to chime with the real world or eventually we grow dissatisfied with it.
Agreed! I will be discussing this more in the future talk ‘From Neural Is to Moral Ought’.
General ideas, especially moral ones, impressed on us at an early age often become deeply embedded in our brains. It can be especially difficult to change them.
And hence it necessarily takes time (indeed generations) for worldviews to change. I will be discussing this more in the upcoming talk ‘What I Know and Why I Know It’.
The very nature of our brains – evolved to guess the most plausible interpretations of the limited evidence available – makes it almost inevitable that, without the discipline of scientific research, we shall often jump to wrong conclusions, especially about rather abstract matters
This chimes with the interpretation of intelligence and hypothesis and prediction explored in the previous talk ‘Intelligence and the Brain’.