I have an issue with the expression 'consciousness surviving the body'. I think it's inherently self-contradictory insofar as consciousness is generally understood to be an attribute of physical organisms and is generally not perceived in any other context. But then, I also think the tendency to see this question in these terms is due to the framework in which this is understood.
There was an opinion piece published in Scientific American, by physicist Sean Carroll, called
Physics and the Immortality of the Soul. Carroll argues that belief in any kind of life after death is equivalent to the belief that the Moon is made from green cheese - that is to say, a ridiculous idea.
But such an assertion is made because of the presuppositions that he brings to the question, the perspective through which he views it. In other words, he depicts the issue in such a way that it would indeed be ridiculous to believe it.
Carroll says:
Claims that some form of consciousness persists after our bodies die and decay into their constituent atoms face one huge, insuperable obstacle: the laws of physics underlying everyday life are completely understood, and there’s no way within those laws to allow for the information stored in our brains to persist after we die. If you claim that some form of soul persists beyond death, what particles is that soul made of? What forces are holding it together? How does it interact with ordinary matter?
I can think of an answer to this question, which is that the soul is not 'made of particles' and that the idea that the soul is 'made of particles' is not at all characteristic of what is meant by the term 'soul'. (Some of the ancient Stoics and Hindus did believe in a form of subtle matter, but I'll leave that aside. And I'll also leave aside the implicit hubris.)
First recall that the Greek term interpreted as 'soul' was 'psuche' or 'psyche' which is of course still with us as a form of a word for 'mind' (preserved in 'psychology'). But I think the soul could be better conceived in terms of a field that acts as an organising principle - analogous to the physical and magnetic fields that were discovered during the 19th century, that were found to be fundamental in the behaviour of particles. This is not to say that the soul
is a field, but that the field analogy might be a better metaphor than particulate matter. (And bearing in mind, in Aristotle, the soul is given as 'the form of the body', where 'form' is akin to 'animating principle'. It is not 'the shape' nor is it conceived of as a separable entity.)
Morphic Fields
So - just as magnetic fields organise iron filings into predictable shapes, so too might a biological field effect be responsible for the general form and the persistence of particular attributes of an organism. The question is, is there any evidence of such 'biological fields'?
Well, the existence of 'morphic fields' is the brainchild of Rupert Sheldrake, the 'scientific heretic' who claims that:
Morphic resonance is the influence of previous structures of activity on subsequent similar structures of activity organized by morphic fields. It enables memories to pass across both space and time from the past. The greater the similarity, the greater the influence of morphic resonance. What this means is that all self-organizing systems, such as molecules, crystals, cells, plants, animals and animal societies, have a collective memory on which each individual draws and to which it contributes. In its most general sense this hypothesis implies that the so-called laws of nature are more like habits.
As the morphic field is capable of storing and transmitting remembered information, then 'the soul' could be conceived in such terms. The morphic field does, at the very least, provide an explanatory metaphor for such persistence. (This also resonates with the idea of the collective unconscious (Jung) and the alayavijnana, the ‘storehouse consciousness’ of Mahāyāna Buddhism. Meaning that the soul or psyche is analogous to a standing wave or whirlpool structure in such a medium, the 'cittasantana' or mind-stream of Mahāyāna Buddhism. )
Children with Past-Life Memories
But what, then, is the evidence for such effects in respect to 'life after death'? As mentioned previously a researcher by the name of Ian Stevenson assembled a body of data on children with recall of previous lives. Stevenson's data collection method comprised the methodical documentation arising from the seeking out and recording of a child’s purported past-life recollections. Then he identified from journals, birth-and-death records, and witness accounts, the deceased person the child supposedly remembered, and attempted to validate the facts from those sources that matched the child’s memory. Another Scientific American opinion piece notes that Stevenson even matched birthmarks and birth defects on his child subjects with wounds on the remembered deceased that could be verified by medical records.
On the back of the head of a little boy in Thailand was a small, round puckered birthmark, and at the front was a larger, irregular birthmark, resembling the entry and exit wounds of a bullet; Stevenson had already confirmed the details of the boy’s statements about the life of a man who’d been shot in the head from behind with a rifle, so that seemed to fit. And a child in India who said he remembered the life of boy who’d lost the fingers of his right hand in a fodder-chopping machine mishap was born with boneless stubs for fingers on his right hand only. This type of “unilateral brachydactyly” is so rare, Stevenson pointed out, that he couldn’t find a single medical publication of another case. — Are We Sceptics Just Cynics?
Carroll goes on in his essay to say that 'Everything we know about quantum field theory (QFT) says that there aren’t any sensible answers to these questions (about the persistence of consciousness)'. However, that springs from his starting assumption that 'the soul' must be something physical, which, again, arises from the presumption that everything is physical, or reducible to physics. In other words, it is directly entailed by his belief in the exhaustiveness of physics with respect to the description of what is real.
He then says 'Believing in life after death, to put it mildly, requires physics beyond the Standard Model. Most importantly, we need some way for that "new physics" to interact with the atoms that we do have.' However, even in ordinary accounts of 'mind-body' medicine, it is clear that mind can have physical consequences and effects on the body. This is the case with, for example, psychosomatic medicine and the placebo effect, but there are other examples.
He finishes by observing:
Very roughly speaking, when most people think about an immaterial soul that persists after death, they have in mind some sort of blob of spirit energy that takes up residence near our brain, and drives around our body like a soccer mom driving an SUV.
But that is
not what 'most people have in mind'. As mentioned above, the idea of a self that transmigrates life to life is condemned in no uncertain terms in Buddhist scriptures, which do otherwise accept the reality of re-birth. But that is what physicalism ‘has in mind’ because it's the only way to conceive of something if you think that all that is real is matter.. If you start from the understanding that 'everything is physical', then this will indeed dictate the way you think about it. And while it may be true that there is no such 'blob' as Carroll describes, that is not what the 'soul' is; but what it might be, is something that can't be understood in the terms of Carroll's ontological presuppositions.
So, I myself don’t much like the terminology of ‘consciousness surviving death’, especially when ‘consciousness’ is defined in terms of an attribute of conscious beings. The fact that we feel compelled to conceive it that way is a consequence of the ‘objectifying’ tendency which is deeply rooted in the way we think about it. But very subtle questions of identify, metaphysics and epistemology underlie this issue.
Physicalism is, in slogan form, the thesis that everything is physical.... The general idea is that the nature of the actual world (i.e. the universe and everything in it) conforms to a certain condition, the condition of being physical. — Stanford Encylopedia of Philosophy, Physicalism