“This is a participatory universe… Observer-participancy gives rise to information,” the visionary physicist John Archibald Wheeler wrote a generation before philosopher Iain McGilchrist asserted that the way we pay attention — the supreme participancy of consciousness in the universe — “renders the world what it is.”

It may be that consciousness evolved not so much to let the universe comprehend itself, as poetically inclined astrophysicists are fond of saying, but to keep us from being overwhelmed by the totality of a universe which we, as living functions of it, can never fully comprehend; to keep us from being crushed by the weight of a reality as vast as space and as deep as time, a whole so absolute and simultaneous that a mind can only hold it in disjointed parts across discreet moments.

These are the immense and intimate questions William Egginton takes up in The Rigor of Angels: Borges, Heisenberg, Kant, and the Ultimate Nature of Reality (public library) — an ambitious effort to trace “the capillaries of coherence flowing from the particular to the universal,” part ode to those who have caught glimpses of that elemental coherence we call truth and part elegy for our destiny as creatures doomed to glimpses only, for we are particles of the totality we yearn to see whole as we go on seeing through our instruments and our theories not the universe but ourselves.

Egginton traces the invisible threads of revelation between Zeno’s thought experiments and Kant’s cathedrals of logic, between Dante’s cosmogony and the discovery of cosmic microwave background radiation, between Plotinus and Heisenberg, in order to illuminate and celebrate how that collaborative tapestry of thought has shaped “our conceptions of beauty, science, and what we owe to each other in the brief time given to us in this universe.” At the center of the book is the recognition that what we know about how the universe works is not a reflection of absolute truth but of our sensemaking — something William Blake intimated in his koan of a lyric that “the Eye altering alters all.” Egginton pulls back the curtain of perception:

Is the saturated red of a Vermeer part of that ultimate reality? The soft fuzz of a peach’s skin? The exalted crescendo of a Beethoven symphony? If we can grasp that such powerful experiences require the active engagement of observers and listeners, is it not possible, likely even, that the other phenomena we encounter have a similar origin? When we do the opposite, we forget the role we have in creating our own reality.

With an eye to Borges — a guiding spirit of the book, who understood that time is the substance we are made of, understood that we have dreamt up the world with our cult of reason but must live in it with the “tenuous and eternal crevices of unreason which tell us it is false” — Egginton considers the limits of observation, our sole lens on reality:

A being who was truly, exclusively saturated in a present moment wouldn’t be able to observe anything at all. Observation, any observation, installs a minimal distance from what it observes, for the simple reason that for any observation to take place, one here and now must be related to another here and now, and that relation needs to be registered by some trace or connector between the two.

Two centuries after Kierkegaard asserted that “the moment is not properly an atom of time but an atom of eternity,” he adds:

The blur of the instant of change that is a logical prerequisite for stitching together any two moments in space-time inextricably inheres in the very reality being observed.

[…]

In a deep sense, then, the laws of physics, the laws that describe how things behave, are really the laws of our observations of how things behave.

Heisenberg’s uncertainty principle — that pillar of quantum physics, which holds that you can know a particle’s position or its momentum, but never both at the same time — cast the challenge of coherence in spacetime into sharp relief, but it was the Platonic philosopher Plotinus who first took the paradox of simultaneity and made of it a model of eternity. Egginton writes:

Plotinus didn’t conceive of eternity as an endless, boring extension of the present. Instead, he imagined eternity as everything, all existence, all space, and all time, captured at once, in the blink of an eye. Eternity wasn’t the endless expansion of time; it was the absolute negation of time. We humans experience things in time because we are limited and cannot fully grasp the absolute unity of all things. The time we inhabit, he taught, is nothing but the moving image of eternity, an insignificant second hand sweeping over the face of a vast, immobile clock, never grasping more than a fraction of its surface. However, we could be certain that this eternity existed. For, as Kant would also see a millennium and a half later, our very ability to experience any given moment in time logically necessitates the existence of a reality that transcends those moments, a greater unity that “upholds things, that they not fall asunder.”

Plotinus went on to inspire Saint Augustine’s “vision that would unite physics and ethics in a strange, new architecture of the cosmos and an ultimate vindication of human freedom.” Naturally, inevitably, the paradox of free will pulsates beneath Egginton’s inquiry — for, if Octavio Paz was right that “without freedom, what we call a person does not exist,” then without freedom there can also be no observer and without an observer there is no world to render real. A generation after Simone de Beauvoir examined how chance and choice converge to make us who we are, Egginton reflects:

It is because I cannot take both roads and still be the same traveler that I imagine them and, in imagining them, and in choosing, am condemned to that very freedom that the godlike knowledge of a mechanistic universe seeks to absolve me of. We seek to render that godlike knowledge real; we contort our imagination and make myths out of math; we brew bubbling Kandinsky multiverses and grow gardens of infinitely forking paths. But the intimate rifts, the interstices of unreason that those models seek to obliterate, are indelible. They inhabit us. They make us what we are.

Echoing Lewis Thomas’s lovely insistence that “we need a better word than chance” to account for how we went “all the way from a clone of archaebacteria, in just 3.7 billion years, to the B-Minor Mass and the Late Quartets,” he adds:

As we steer a course through the river of our lives, we are affected by innumerable forces, the vast majority unknown to us. By some accounts this makes of our freedom an illusion, for how can we purport to freely choose when we can’t even see a fraction of the legion of influences acting on us, limiting our movements, sparking our appetites? The threat this picture poses to traditional notions of agency suggests a counternarrative. There must be some part of us that floats above the river, untouched by its waters and therefore utterly free and totally responsible for our every turn. But both these pictures are misleading, and for the same reason. Our freedom, and hence our responsibility for the choices we make, is neither a thing to look for in our material existence nor some ghostlike essence unmoored from that existence. Rather, it is a necessary postulate for a being who can imagine having chosen differently, the condition of the possibility of conceiving of that life as one possible path among many.

Inseparable from the question of freedom is the nature of the imagination — that ultimate frontier of our freedom of thought. In a passage evocative of the poetic physicist Alan Lightman’s insight into the shared psychology of creativity in science and art, Egginton considers the fruits of that freedom:

In a satisfying work of art, the ensemble of its elements conforms to its internal principle, the idea that guides it. Thus, when we come to the end of a mystery novel, the solution appears inevitable, although we couldn’t see it coming. Likewise, when we find a theoretical explanation for the seemingly random events of the natural world, we feel the same aesthetic satisfaction as with a well-wrought plot or a masterfully composed symphony: we thrill to the diversity of nature expressing the idea of its order, its inherent rigor. That guiding principle that we read in nature or in art appears to us its purpose. But just as the work of art ignites our aesthetic judgment only when its creator has erased the signs of artifice, so our understanding of the natural world is led by a silent conviction that the universe that unveils itself before our eyes works toward an end and purpose, one it expresses from the greatest cataclysms of galaxies down to the most intimate crevices of possible perception, and yet one that was never meant, never intended, never planned by angel, god, or human mind, other than our own.

That purpose and meaning are not inherent to the universe but our own creation, that all of our reckonings with the nature of reality are a mirror we hold up to ourselves, is at the heart of The Rigor of Angels. Egginton reflects:

No matter where we train our gaze on the starry skies above, we look inward toward the very origin of space and time. Thus freeing our minds from our senses, we find that the universe is, indeed, turned inside out.

[…]

We ultimately realize what we are striving for lies inside us; we find ourselves in the world and the world in ourselves.

Complement with quantum pioneer Erwin Schrödinger, writing nearly a century ago, on the universe and the mystery of what we are and physicist Brian Greene on our cosmic search for meaning, then revisit Marie How’s poem “Singularity” — that magnificent quickening of thought and feeling, giving shape to the deepest human yearnings in a cosmos indifferent to our fate, insentient to our freedom.