This post is part of a series on the philosophical and spiritual views of prominent scientists and mathematicians. Future subjects will include Georg Cantor, Albert Einstein, Werner Heisenberg, and Barbara McClintock.
But Schrödinger also had a deep appreciation for philosophy and theology. Like other physicists of his time (including Einstein) he was influenced by the ideas of Schopenhauer and Spinoza, philosophers with heterodox concepts of God and reality. He expressed particular admiration for Hindu metaphysics, with a focus on Vedanta.
Let’s explore Schrödinger’s philosophy and see how it emerges from and coheres with his scientific work.
Schrödinger’s love for philosophy took root at an early age, and continued throughout his scientific career. His was incessantly curious about the world, and worked constantly to better understand it.
He described his attitude as one of “philosophical wonder,” and was stunned by the bizarre and intricate complexity of the world:
Surely astonishment and wonder are what we feel on encountering something that differs from what is normal…But this whole world is something we encounter only once. We have nothing with which to compare it, and it is impossible to see how we can approach it with any particular expectation. And yet we are astonished; we are puzzled by what we find, yet are unable to say what we should have to have found in order not to be surprised, or how the world would have to have been constructed in order not to constitute a riddle!
He developed an early interest in Plato and Hume, and in his father’s library he discovered some obscure works on Buddhist and Hindu philosophy. Later, after having established himself as a physicist (but before his crowning achievements), Schrödinger began to devour Kant, Schopenhauer, and Spinoza, hoping that he might be able to split his time between teaching physics and writing about philosophy.
Schrödinger saw philosophy as a complement to scientific understanding:
These phenomena of value judgement, wonder and riddle-finding…[have never] been grasped either by formal logic or, still less, by exact science: [they] keep forcing us back towards metaphysics; that is, towards something that transcends what is directly accessible to experience
And saw them as mutually reinforcing:
I am now talking religion, not science - a religion, however, not opposed to science, but supported by what disinterested scientific research has brought to the fore.
Fortunately, he spent a couple of decades building the foundations of quantum mechanics before beginning his philosophical career in earnest.
In 1944, at the age of 57, Schrödinger published the first of his most important philosophical essays: What is Life?. While the main chapters don’t explicitly deal with metaphysics or theology, they show how Schrödinger was able to take his deep knowledge of physics and extrapolate an intuition for other domains: What is Life? was credited by both Watson and Crick as an inspiration for their work on the structure of DNA.
The main problem What is Life? sets out to solve is how the rich biology of life emerges from the mechanisms of physics and chemistry. This is a natural problem for Schrödinger to work on, given that he effectively solved the problem of how chemistry emerges from physics.
Life, Schrödinger points out, presents us with a paradox: genes are so small that they should behave chaotically, and yet we see remarkable stability spanning generations. He resolves the paradox by positing a new kind of physical structure, not yet observed by chemists or physicists: the aperiodic crystal, a prelude to the double helix of Franklin, Watson, and Crick.
The epilogue to What is Life? examines the book’s philosophical implications. Having shown that life is a product of physical mechanisms, Schrödinger tries to resolve the paradox of free will:
So let us see whether we cannot draw the correct, non-contradictory conclusion from the following two premises:
(i) My body functions as a pure mechanism according to the Laws of Nature.
(ii) Yet I know, by incontrovertible direct experience, that I am directing its motions, of which I foresee the effects, that may be fateful and all-important, in which case I feel and take full responsibility for them.
The only possible inference from these two facts is, I think, that I—I in the widest meaning of the word, that is to say, every conscious mind that has ever said or felt “I”—am the person, if any, who controls the “motion of the atoms” according to the Laws of Nature.
This is a bold theological statement, and Schrödinger admits as much:
…it is daring to give to this conclusion the simple wording that it requires. In Christian terminology to say: “Hence I am God Almighty” sounds both blasphemous and lunatic. But please disregard these connotations for the moment and consider whether the above inference is not the closest a biologist can get to proving God and immortality at one stroke.
He doesn’t claim credit for the idea, which he traces the idea back to the Upanishads. He says it is the central revelation of all mystics across cultures and centuries, referring the reader to Aldous Huxley’s The Perennial Philosophy.
How, exactly, 8 billion humans are all the ones controlling the “motion of the atoms” is a question Schrödinger acknowledges, but it’s not until his last book that he starts to address it in earnest. We’ll come back to this question in a bit.
Having discovered precisely how chemistry emerges from physics, and aided in the discovery of how biology emerges from chemistry, Schrödinger took on the hard problem of how psychology emerges from biology in his book Mind and Matter.
Schrödinger puts the question here quite simply: “What kind of material process is directly associated with consciousness?”
He accepts that he is stepping out of the domain of science, but insists that the logical positivist’s refusal to engage with the subject is shortsighted:
A rationalist may be inclined to deal curtly with this question, roughly as follows. From our own experience…consciousness is linked up with certain kinds of events in organized, living matter, namely, with certain nervous functions. How far back or “down” in the animal kingdom there is still some sort of consciousness, and what it may be like in its early stages, are gratuitous speculations, questions that cannot be answered and which ought to be left to idle dreamers…
He who accepts this brushing aside of the question ought to be told what an uncanny gap he thereby allows to remain in his picture of the world.
Schrödinger’s “tentative answer” to the problem is that consciousness is associated with learning and adaptation. We are only conscious when confronted with novelty; once a phenomenon or behavior becomes predictable or habitual, it fades in to unconsciousness.
I would summarize my general hypothesis thus: consciousness is associated with the learning of the living substance; its knowing how (Können) is unconscious.
Importantly, he claims this is not only a property of nervous systems, but of all adaptive organic processes:
What in the preceding we have said and shown to be a property of nervous processes is a property of organic processes in general, namely, to be associated with consciousness inasmuch as they are new.
His argument is that the physical substrate doesn’t matter—only the process. He points out that much of our nervous system is unconscious, and the entire thing is unconscious in deep sleep. The only difference between conscious and unconscious neurons is their engagement in learning, adaptation, and novelty.
Schrödinger never really identifies the point at which a process makes the binary switch between consciousness and unconsciousness, and instead speaks in terms of a continuum. But he does seem to make a strong binary distinction between organic and inorganic matter (in a later work, he pokes fun at Fechner’s idea that stars and planets might be conscious).
In other words, he doesn’t really provide an answer to the hard problem of “what kind of material process is directly associated with consciousness”; he only tries to narrow the search space.
Schrödinger traces the hardness of the mind-body problem back to what he calls the Principle of Objectivation—a pillar of science that abstracts away subjectivity in order to produce objective results. He defines Objectivation as:
the thing that is also frequently called the “hypothesis of the real world” around us. I maintain that it amounts to a certain simplification which we adopt in order to master the infinitely intricate problem of nature.
The issue, he explains, is that the scientist treats himself as an external observer peering into the universe from outside. We make our model of the universe perfectly objective by removing our own subjectivity (i.e. qualia) from it:
…a moderately satisfying picture of the world has only been reached at the high price of taking ourselves out of the picture, stepping back into the role of a non-concerned observer.
The reason why our sentient, percipient and thinking ego is met nowhere within our scientific world picture can easily be indicated in seven words: because it is itself that world picture.
He points out two main problems that arise from Objectivation:
The first of these antinomies is the astonishment at finding our world picture 'colourless, cold, mute'. Colour and sound, hot and cold are our immediate sensations; small wonder that they are lacking in a world model from which we have removed our own mental person.
The second is our fruitless quest for the place where mind acts on matter or vice-versa…The material world has only been constructed at the price of taking the self, that is, mind, out of it, removing it; mind is not part of it; obviously, therefore, it can neither act on it nor be acted on by any of its parts.
Schrödinger doesn’t offer any concrete ideas on how to reincorporate subjectivity into our scientific worldview, but he suggests that we should look toward Eastern philosophy for the answer.
(Note: some sources, including Google, claim this was written in 1951, but as best I can tell it’s a viral typo. My edition and Britannica agree on 1961.)
In his last book, My View of the World, Schrödinger delves deeper into the problems with Objectivation, calling into question the hypothesis of an objective, external reality. That a physicist should treat objective reality as merely an hypothesis—and one that should be discarded—is strange, but Schrödinger insists:
I have therefore no hesitation in declaring quite bluntly that the acceptance of a really existing material world…is mystical and metaphysical. Nevertheless, anyone who wants to make it can do so; it is convenient, if somewhat naive. He will be missing a great deal if he does. But he certainly does not have the right to pillory other positions as metaphysical and mystical on the supposition that his own is free from such ‘weaknesses’.
Schrödinger points out that it only makes sense to talk about a “real world” when we consider multiple agents observing that world; a single agent would have no need to distinguish between its direct perceptions and some external cause for those perceptions. (Surprisingly, this is the closest Schrödinger comes to discussing solipsism, which would be the easiest way out of his paradox.)
When we communicate with other agents, we begin to surmise the presence of an external reality:
The broad measure of agreement between two observed worlds, let us say B and B’, is to be explained by some sort of correspondence with the real world, R, that is of B with R and of B’ with R. Anyone who thinks like this is forgetting that R has not been observed. No one perceives two worlds, one observed and one ‘real’, no one is in a position to establish any sort of similarity in their structure.
But with or without R, we need to grapple with the “broad measure of agreement” between the observed worlds B and B’:
But the knowledge is there, really there, as real as the private worlds themselves. We want to know where it comes from. This is a valid question: how do we come to know of this general agreement between two private worlds, when they admittedly are private and always remain so?
So we have another conundrum: how can two people bootstrap a scheme of communicating without ever feeling what the other feels? Schrödinger draws from a number of examples in biology and psychology to demonstrate that the core mechanism here is mimicry: people learn by imitating one another.
This leads to a great leap: mimicry creates an overlap in their subjective experience. As they move through the same motions, they feel the same things, and each effectively has access to some part of the other’s subjective mind—two separate minds begin to merge into one.
He acknowledges that this is a strange idea:
This conclusion…immediately strikes us westerners as thoroughly bizarre. [We] have accustomed ourselves to thinking…that each person’s sensation, perception and thought is a strictly segregated sphere, these spheres having nothing in common with each other, neither overlapping nor directly influencing each other, but on the contrary absolutely excluding each other.
It’s from here that we start to understand Schrödinger’s most radical belief: that there is, in reality, only a single Mind.
He initially stated this hypothesis in What is Life?, after his discussion of free will:
[The paradox] will be solved (I do not pretend to solve [it] here and now) by assimilating into our Western build of science the Eastern doctrine of identity. Mind is by its very nature a singulare tantum. I should say: the over-all number of minds is just one.
In My View of the World, he starts to address the paradox of how billions of separate individuals might only be aspects of a single Mind:
Shared thoughts, with several people really thinking the same thing…really are thoughts in common, and they are single occurrences; any numerical statement about how many of them there are, based on a count of the number of individuals engaged in thinking, is quite without meaning in respect of what is being thought.
He takes this conclusion pretty far, saying:
close intellectual collaboration between two men can bring about to an incredible degree a fusing of their spheres of consciousness in an empirical unity
Nor can one say that the suffering of twenty or a thousand mothers who lose
their sons in a single battle is twenty or a thousand times that of one single
mother thus afflicted. Nor is the pleasure enjoyed when twenty or a thousand
young men sleep with their girls twenty or a thousand times as great as when this
only happens in a single case.
While I follow Schrödinger’s argument, the universe he’s describing is so alien to me that I have a hard time holding onto it. It’s common sense that a thousand grieving mothers generate more grief than just one.
But what if we hold the number of deaths constant: do two parents grieving the death of their child generate more grief than a single parent would? This example I’m not as sure about.
So according to Schrödinger, the universe is a single Mind, which (for reasons unspecified) partitions itself into a vast array of overlapping subjective spheres. What we call physical “external” reality just consists of the most stubborn overlaps. Schrödinger admits this is not a scientific assertion, but a mystical and metaphysical one. Nonetheless, this heterodox view of reality seems to have given Schrödinger some unique insight, given his incredible contributions to physics.
I find it strange that, despite his love for Hindu and Buddhist theology, Schrödinger never seems to have taken up any yogic or meditative practice. Michel Bitbol hypothesizes that Schrödinger looked at sex and love through a tantric lens, and that through them he accessed the ecstatic states that typically undergird this type of mysticism. He quotes Schrödinger as saying
Love a girl with all your heart and kiss her on her mouth: then time will stand still and space will cease to exist.
I’d be remiss if I didn’t mention at this point that Schrödinger serially preyed on young women, even trying to seduce his twelve-year-old cousin. Basing your religious perspective on sexual contact (or abstinence!) is a formula for disaster.
But the depth of Schrödinger’s scientific insights leaves me sympathetic to the idea that he may have had some strong philosophical insights as well. In his own mind, the two certainly reinforced one another.
As I continue this series, it will be interesting to see how well his ideas cohere with those of some other famous scientists, especially his colleague, Werner Heisenberg.
This part of Mind and Matter felt like a bit of a distraction from the core of Schrödinger’s philosophy. In it, he makes the case that one vein of science has helped to shed light on philosophical questions: an increasingly sophisticated conception of time, as articulated by Plato, Kant, and Einstein.
Plato’s contribution was being “the first to envisage the idea of timeless existence and to emphasize it—against reason—as a reality, more real than our actual experience”. Schrödinger is speaking, of course, about the concept of Platonic Realism, the idea that mathematical truths exist independently of physical and mental reality.
[Plato] recognized and absorbed deeply into his mind the nature of these revelations, that they unfold themselves by pure logical reasoning, which makes us acquainted with true relations whose truth is not only unassailable, but is obviously there, forever; the relations held and will hold irrespective of our inquiry into them. A mathematical truth is timeless, it does not come into being when we discover it. Yet its discovery is a very real event, it may be an emotion like a great gift from a fairy.
This sets up a prototype for western mysticism: a Higher Eternal Truth, independent of the physical world, pieces of which are revealed to select minds.
(But by a fairy?)
Kant’s contribution was the realization that we can never know a “thing-in-itself,” but can only know it through indirect sensations, and that this applies to space and time as well as physical objects. There are echoes here of Schrödinger’s B and B’ versus R argument.
The idea that space and time are mental constructs, rather than some inherent part of objective reality, opens up a world of metaphysical possibility:
For instance—to speak of the most momentous example—experience as we know it unmistakably obtrudes the conviction that it cannot survive the destruction of the body, with whose life, as we know life, it is inseparably bound up. So is there to be nothing after this life? No. Not in the way of experience as we know it necessarily to take place in space and time. But, in an order of appearance in which time plays no part, this notion of “after” is meaningless. Pure thinking cannot, of course, procure us a guarantee that there is that sort of thing, But it can remove the apparent obstacles to conceiving it as possible. That is what Kant has done by his analysis, and that, to my mind, is his philosophical importance.
In other words, the idea that a core component of our ontology—time—is merely a mental projection, leaves the door open to all sorts of possibilities (like eternal life) that would have otherwise been logically ruled out.
Schrödinger summarizes Einstein’s contribution to our concept of time in two main points:
(1) The notion of 'before and after' resides on the 'cause and effect' relation…
(2) …[and] effects do not spread with arbitrarily high velocity.
This leaves us with pairs of events that are not entirely ordered: in one frame of reference, A occurs before B; to another observer, B occurs first.
Schrödinger says this revelation
…meant the dethronement of time as a rigid tyrant imposed on us from outside, a liberation from the unbreakable rule of “before and after”. For indeed time is our most severe master…To be allowed to play about with such a master's programme believed unassailable until then, to play about with it albeit in a small way, seems to be a great relief, it seems to encourage the thought that the whole “timetable” is probably not quite as serious as it appears at first sight. And this thought is a religious thought, nay I should call it the religious thought.
He goes on to describe the work of Boltzmann in creating a statistical view of time through his work on entropy. The successful theories of Einstein and Boltzmann demonstrate for Schrödinger two major points:
that our common-sense conception of time is deeply limited
that we can, through our efforts, develop a deeper understanding of time
and one huge implication:
This means a liberation from the tyranny of old Chronos. What we in our minds construct ourselves cannot, so I feel, have dictatorial power over our mind, neither the power of bringing it to the fore nor the power of annihilating it. But some of you, I am sure, will call this mysticism. So with all due acknowledgment to the fact that physical theory is at all times relative, in that it depends on certain basic assumptions, we may, or so I believe, assert that physical theory in its present stage strongly suggests the indestructibility of Mind by Time.
I don’t understand how he arrives at such a strong conclusion from the premises (the argument on free will above was much easier to follow), but anyone would start to get dizzy after stewing on the idea of “time as mental construct.”
As he points out, when you rip out the foundation of your ontology, anything becomes possible.