1. A Visitor to the Plane↗
Suppose you are an ant.
Not an actual ant, but an imagined creature confined to a two-dimensional plane. You can move forward, backward, left and right, but have never directly experienced “up.” Your world is as flat as an endless sheet of paper.
One day, a sphere passes through the sheet. A cross-section appears within the plane: small at first, then larger, then smaller again, until it vanishes. You cannot step out of the plane and walk around the sphere to see it whole.
What would you call this? A thing that changes size, perhaps; a trick; a miracle. Without a ready concept, explanation borrows from the words already available. But lacking an explanation does not compel you to accept any one of these answers.
The thought experiment resembles the sphere’s visit to the two-dimensional world in Flatland. Its interest lies not only in what a lower-dimensional creature cannot see, but in whether something beyond direct perception might still be inferred.
Now return to humans.
2. A Moving Threshold↗
Imagine someone with no knowledge of electrical discharge standing in open country. The sky splits with light. A tree is struck and begins to burn.
What has this person seen?
Perhaps an angry sky: a power capable of taking life. This is an imagined scene, not a report of a shared prehistoric psychology, much less an explanation of the origin of every religion.
Lightning later acquires a physical explanation. That does not make everyone cease believing in gods; faith need not consist solely in filling gaps in natural knowledge.
I want to examine one use of the idea: placing “god” on a moving threshold, giving a name to what has not yet been explained.
As understanding advances, this use retreats. Beyond lightning lie the origin of the universe, the nature of consciousness, the direction of time, the reason for existence.
The threshold moves. This describes a strategy of explanation, rather than the only meaning of “god” or a proof for or against divine existence.
3. Black Blood and Miracles↗
Borrow a science-fiction motif and imagine this story. After a nuclear catastrophe, one group retains some technology while another suffers a severe break in the transmission of knowledge. The first possesses a fictional blood-altering technology. Those modified can withstand radiation that others cannot, and their blood turns black.
Black blood is a premise of the story, not a real method of radiation protection. Nor does the story equate a loss of technical knowledge with a loss of human worth.
One day, the groups meet.
People unfamiliar with the technology see someone enter a place of death and survive. They see blood unlike their own. Perhaps they say: these people have been chosen; black blood is a sacred mark.
They need not be lying or foolish. They may be using the concepts they have to name a phenomenon they do not yet understand.
They might also doubt, observe, experiment or withhold an explanation. “Miracle” is not the only answer available when concepts are lacking.
In this story, a technical and a sacred explanation address the same event but undertake different commitments. One describes conditions and processes; the other may also confer identity, authority and meaning. Learning how black blood is produced does not automatically settle whom to obey.
4. Beyond Three Dimensions↗
Take the thought a step further. Suppose there is a fourth spatial dimension, and some creature can move along it. This is a mathematical and fictional premise, not the discovery of such a civilization.
An observer confined to a three-dimensional cross-section might encounter only part of the visitor. A structure appearing, changing and disappearing within the section need not have come into existence or been destroyed in the larger space.
4.1 A Cross-Section↗
The equation of a sphere in four-dimensional Euclidean space makes the point more precise:
Here is the radius, and are four spatial coordinates. Restricting observation to the three-dimensional hyperplane gives an ordinary spherical surface of radius when . At equality, it becomes a point; beyond it, there is no intersection.
Successive sections can therefore grow and shrink. Varying does not turn the fourth spatial coordinate into time. The equation describes geometry, not life, consciousness or divinity.
4.2 An Extra Dimension Is Not Omniscience↗
An additional direction of motion might geometrically permit a route around some lower-dimensional barriers. It does not automatically provide vision through all matter, presence at arbitrary places at once or the power to create a universe. Such abilities require additional physical conditions, and may not be possible at all.
In particular, a fourth spatial dimension does not imply simultaneous sight of past, present and future. Four-dimensional spacetime in relativity combines three spatial dimensions with one of time. Their relationship does not abolish causal structure or allow an observer to survey all events at will.
Flatland even lets the sphere point out that seeing what planar inhabitants cannot see does not make a visitor more just, merciful or worthy of worship. A difference in ability and a claim to divinity are separated by an argument still to be made.
5. Beyond the Boundary↗
In some uses, then, “god” may mark a boundary of knowledge. The marker does not tell anyone what lies beyond it.
A phenomenon may have an undiscovered natural explanation. The question may need to be reorganized. Even “what lies beyond?” may import a spatial image that does not belong.
Not knowing leaves room for conjecture. It does not make every conjecture equally credible.
Being imaginable is not evidence; lacking an explanation does not make every explanation valid.
An experience that is difficult to express cannot be identified as a signal from a higher-dimensional civilization merely because words fail. It deserves careful description, alongside a distinction between what occurred and what an interpretation adds.
People centuries ago might not have anticipated today’s technologies. That warns against closing possibility too soon. It does not supply evidence for any particular present conjecture. A surprising future does not excuse an unsupported argument now.
We do not know what we do not know. For that very reason, the unknown should not be made to guarantee a chosen answer.
6. Thresholds That Can Be Crossed↗
I think two honest attitudes can remain available at a boundary.
First, not knowing today need not mean not knowing tomorrow.
Many phenomena once difficult to understand have acquired better explanations. Standing at a threshold is no reason to declare an endpoint and forbid further questions.
The observer on the plane need not cry “miracle” forever. Even without personally moving upward, it might compare hypotheses through changing cross-sections and look for repeatable relations. Human mathematics, instruments and collective inquiry likewise take knowledge beyond direct perception.
Awe need not end inquiry.
7. Thresholds That May Remain↗
Second, human cognition need not be unlimited.
People have particular bodies and cognitive capacities. Research also depends on finite resources, observations and time. That is enough to make eventual understanding of everything a promise requiring reasons.
But having evolved does not prove that consciousness, time or existence must remain inexplicable forever. Lacking a direct intuition is different from lacking a concept. What one person cannot accomplish may still advance through tools and shared inquiry.
A fish and the feeling of dryness can suggest an experience difficult to share. They do not establish that knowledge about fish, water and sensation is unavailable. Acquaintance, imagination and explanation are different abilities.
At least three situations need distinguishing: a question currently unanswered, a question beyond present methods, and a question supported by good reasons for being unanswerable under specified conditions. These are different walls.
The hardest honesty may be admitting that the kind of boundary ahead is not yet known.
8. At the Threshold↗
Some thresholds have been crossed. Others may keep people standing before them for a long time. Some apparently impenetrable walls turn out, after a change of question, to have been built by language.
This does not require suspending judgment on every particular claim. Judge where evidence permits; withhold where it does not. Different claims must carry their own reasons.
In the use examined here, “god” can be a threshold. The image draws attention to ways of facing the unknown. It does not let the unknown certify either belief or disbelief.
An honest person need not already recognize every eternal boundary. Perhaps what matters more is neither stopping too soon where inquiry remains possible, nor pretending to have crossed where knowledge has not yet reached.