One Rule For All - Immanuel Kant and the Problem of Moral Consistency

What makes a rule legitimate? Not merely power. Not popularity. Not convenience.

For the German philosopher Immanuel Kant (1724–1804), a moral principle only carries real authority if it applies universally—not just to other people, but to ourselves as well.

This idea became one of the foundations of Kant’s moral philosophy: the Categorical Imperative.

In one of its most famous formulations, Kant wrote:

“Act only according to that maxim whereby you can at the same time will that it should become a universal law.”

The idea sounds abstract at first, but its implications are surprisingly practical.

Before acting, Kant asks us to consider a difficult question. What if everyone acted this way?  Not occasionally. Not selectively. Universally.

Could the principle still function fairly and rationally if applied to all people equally?  If the answer is no, then the action fails the test.

A person who lies for convenience while expecting honesty from everyone else creates a contradiction. A person who demands fairness only when personally disadvantaged is not defending a principle at all—they are defending preference.

Kant’s philosophy challenges the human tendency toward exceptions, especially self-serving ones.

The Problem With Double Standards

Most people recognize hypocrisy immediately when it appears in others.

We become frustrated when:

• rules are enforced selectively
• accountability depends on status
• or principles suddenly change depending on who benefits

Even societies themselves begin to weaken when citizens no longer believe standards apply equally.  Trust erodes.  Institutions lose legitimacy.  Public life becomes increasingly tribal, cynical, and unstable.

The problem is not simply disagreement. Free societies will always contain disagreement.  The deeper danger emerges when moral or civic rules are treated as flexible tools rather than universal standards.

A society cannot function for long if every principle contains invisible exceptions.

Universal Principles and Human Dignity

Kant believed morality was rooted in reason itself, not merely emotion, popularity, or custom.

This led him to another influential moral principle: human beings should never be treated merely as means to an end, but always as ends in themselves.

In practical terms, this means people possess dignity that should not depend on tribe, utility, wealth, power, or political usefulness.

The principle remains relevant because modern societies still struggle with the same temptation Kant identified centuries ago. To demand universal behavior from others while quietly reserving exceptions for ourselves.

Why It Still Matters

The modern world moves quickly. Outrage changes daily. Public standards often shift according to ideology, loyalty, or convenience.

Yet the underlying question remains remarkably old. Should moral rules apply equally to everyone?

Kant’s answer was uncompromising. A principle only has meaning if we are willing to live under it ourselves.

That does not make moral life easy. In fact, Kant’s philosophy is demanding precisely because it resists shortcuts and selective reasoning.

But there is also something stabilizing about the idea.  Universal standards create the possibility of trust.  Without them, fairness becomes negotiable.  And once fairness becomes negotiable, principles slowly dissolve into power.

This is the core of the phrase: "One Rule For All".  It reflects this enduring idea, that moral consistency matters, and that rules only carry legitimacy when they apply equally to everyone—including ourselves.

Related reading: The Enduring Shadow of Hypocrisy: Lessons from Philosophy