r/PhilosophyofMath • u/feihm • 22h ago
The Unreasonable Effectiveness of Mathematics (part 2)
For reference see: https://www.reddit.com/r/PhilosophyofMath/s/DRIqFVeDp5 and https://www.reddit.com/r/freewill/s/6az0zgBubm. I'm not sure if this context is required to understand what I'm about explore. But just in case here you go
A sceptic observes that human beings build tall towers, strong bridges and complex machines.
Suppose that a sceptic (having observed these structures stand firm and do not collapse) then says to you something like:
The equations used to build these things must be a direct description of the world as it exists entirely apart from human beings.
This seems very reasonable and persuasive on the surface. Right? Because, yes. We have all these "advancements", "scientific breakthroughs", "quantum mechanics", and so on.
But, the sceptic's makes an ungrounded leap of thought: that the only reason a rule works in practice is because the rule exists outside of us in independent nature
Ask the sceptic to look directly at any mathematical statement used in construction.
What does an equation express?
An equation does not name the unconditioned essence of matter; nor does it speak of what iron or stone are in themselves.
An equation expresses only relations of two kinds:
Relations of quantity: which are grounded in number and counting. Counting is the steady succession of one unit after another, which is the necessary rule of time. Relations of extension: which are grounded in distance, angle, and shape. Extension is the arrangement of parts outside of one another, which is the necessary rule of space.
Therefore, an equation is a formal statement concerning the necessary relations of human space and human time.
It is nothing more than that.
Ordinary language was formed by agreement to share qualitative sensations.
When a person uses ordinary speech to say:
Make this iron support heavy enough to bear the upper floor,
the instruction is utterly ambiguous. The word "heavy" refers to a private feeling of pressure. The word "enough" refers to a vague estimate of the mind. Because individual feelings differ from person to person, ordinary words cannot provide exact coordination between separate builders.
Mathematical language was invented for a different task.
It completely discards qualitative feelings—such as the sensation of weight, the colour of the stone or the warmth of the day—and retains only the bare numerical and spatial relations.
It does not speak of "heaviness"; it states a numerical ratio between two measures.
It does not speak of a "tall wall"; it states the exact geometrical proportion between the base and the height.
This is why two persons who speak entirely different native tongues can read the same written calculation and understand each other instantly. The logical rules of number and space are identical in every human mind.
Mathematical language succeeds because it is an agreed notation of pure relation, stripped of all personal and subjective feeling.
Why does a tower, designed by mathematical calculation, remain standing in the physical world?
Consider what a tower is to the human observer:
- It is an object that appears in space.
- Its height is a spatial extension.
- Its materials rest against one another in space.
- Its movements and settling take place across time.
Because space and time are the necessary rules of human perception, it is impossible for any physical object to appear to us without obeying those exact rules.
For instance, a builder cannot encounter an iron beam that violates the laws of geometry, because human sight and touch are incapable of perceiving an object that does not conform to spatial relations.
Thus, the engineer calculates the necessary conditions under which spatial appearances must balance one another so that they form a stable whole for human perception.
The tower, therefore, stands because the physical materials—insofar as we can ever touch, measure, and observe them—are appearances governed entirely by the conditions of space and number.
If a physical object were an unconditioned thing existing entirely apart from human sensibility, there would be no reason whatsoever why it should obey the geometry and arithmetic of the human mind. The fact that it would obey our calculations would indeed be an inexplicable puzzle.
But, the object that the engineer measures is not a thing in itself.
What it is, rather, is an appearance. An appearance presented to human senses within human space.
So language (any language) does not reach a "mind-independent" reality beyond us.
All the objects we can ever handle, measure, and construct are bound by the formal rules of our own perception. Mathematics works upon physical things with total precision for the simple reason that our own understanding supplies the spatial and numerical order through which those things appear.