All Truth Is Conditional

Beyond absolutism and relativism

Water boils at 100°C. It is hard to imagine a safer candidate for a plain, simple truth. Yet take it up a mountain and it fails. Add a little salt and it fails. State it fully and the simple truth turns out to be something else: water boils at 100°C at sea level, under standard atmospheric pressure, assuming pure H₂O, measured with calibrated instruments, ignoring impurities and experimental error. The conditions extend much further than the casual claim suggests, and the same is true everywhere you look:

• Objects fall at 9.8 m/s² — only near Earth’s surface, ignoring air resistance, neglecting the relativistic curvature of spacetime.
• The angles of a triangle sum to 180° — only within Euclidean geometry, which itself presupposes a flat metric and the parallel postulate.
• The sun rises at 6 a.m. — only at a given location and date, assuming the Gregorian calendar, a conventional definition of sunrise, and no atmospheric refraction.

Every “simple truth” is compressed shorthand for an entire lattice of background assumptions. Notice what this observation does not say. It does not say the claims are false, and it does not say they are matters of opinion. Water really does boil at 100°C under the stated conditions; that is a fact about the world, not about us. What the observation says is that the truth of the claim lives in the whole conditional, not in the bare sentence. Taking that seriously leads to a position I call Conditionalism, and it is the escape route from the oldest false choice in philosophy.

The False Choice

Public debate about truth is trapped between two dead ends. Absolutists claim truth is context-independent, universal, and eternal. Relativists claim truth is contingent on culture, perspective, or identity. Each side sustains itself mainly by pointing at the other: the absolutist warns, correctly, that relativism corrodes rational discourse and morality; the relativist observes, correctly, that every alleged absolute turns out to rest on somebody’s unexamined assumptions.

Alan Rome speaks for many defenders of absolute truth when he argues that the cure for relativism’s corrosion is a return to belief in absolutes. He is right about the disease and wrong about the cure — resurrecting absolutes repeats relativism’s mistake in reverse. Absolutism denies the hidden assumptions it rests on. Relativism denies the very possibility of meaningful discourse across perspectives. Both positions collapse under their own weight, and for the same underlying reason: both treat “true, full stop” and “true for me” as the only options on the table. They are not.

Why Relativism Fails

Relativism is incoherent because it makes an absolute claim: it is universally true that all truth is relative. It eats itself alive. This is not a debater’s trick; it is the fatal structural flaw. A relativism modest enough to apply to itself has no force, and a relativism strong enough to have force is self-refuting.

Worse, relativism dissolves the possibility of critique. If moral claims are only ever true relative to a culture, then condemning slavery or genocide can never be more than an expression of parochial taste — the slaveholding culture’s standards are, by hypothesis, as valid for it as ours are for us. You lose the ability to appeal across vantage points, which is precisely what moral argument is for. Relativism is not humility. It is surrender.

Why Absolutism Fails

Absolutism is incoherent for the complementary reason: it pretends to speak without conditions while smuggling them in. “Murder is always wrong” sounds unconditional. But it silently depends on a definition of murder (which killings count?), on assumptions about agency and responsibility, and on a commitment to valuing human life. None of those dependencies disappears when we refuse to state them; they just operate in the dark.

Masking the dependencies is what makes absolutist reasoning fragile and absolutist disputes interminable. What one side treats as a self-evident absolute, the other side exposes as a contested assumption — and because the absolutist’s framework has no vocabulary for its own conditions, the dispute can only be repeated, never resolved. Absolutism is not strength. It is blindness.

What Conditionalism States

Conditionalism is the thesis that every truth claim depends on conditions, implicit or explicit — and that, in consequence, only conditional statements, statements of the form if X, then Y, can meaningfully bear truth values. Truth is not absolute (“X is true, full stop”). Truth is not relative (“X is only true for me or my group”). Truth is conditional validity relative to specified assumptions.

The argument for this has three steps:

1. Every truth claim requires interpretation. A string of words does not evaluate itself; someone or something must fix what it means before asking whether it holds.
2. Every interpretation requires background conditions. Interpretation leans on linguistic conventions, conceptual frameworks, axiomatic systems, observational parameters. There is no view from nowhere to interpret from.
3. Therefore only conditional statements can meaningfully bear truth values. The conditions are doing load-bearing work whether we state them or not; a statement evaluated apart from its conditions has not yet been given anything to be true of.

The conditions usually stay implicit, and for everyday purposes that is fine — “water boils at 100°C” is a perfectly serviceable compression when everyone shares the background. Even the strongest apparent counterexamples — logical tautologies, mathematical theorems — depend on hidden conditions: a choice of logic, a set of axioms, conventions fixing what the symbols mean. Every attempt to produce a genuinely unconditional truth ends the same way, with the conditional dependencies exposed. Conditionalism’s job is to surface the conditions when it matters: when frameworks clash, when a “simple truth” is pushed beyond the domain its silent conditions define, or when a statement’s conditions cannot be filled in at all and it turns out to say nothing — cases I take up in when statements fail.

The position is a close cousin of Quinean holism, which teaches that statements face experience together rather than one by one, and of Wittgenstein’s insight that meaning lives inside language games. Conditionalism sharpens both into a claim about truth itself: it is not merely that statements are tested in bundles, but that truth values attach only to conditionals — to statements evaluated given their background, never to statements floating free of one. What it takes for a conditional statement to be true — the layered work of pragmatic success, correspondence, and coherence — is the subject of the three levels of truth.

Stronger, Not Weaker

The immediate objection is that conditional truth sounds like diluted truth — that adding “given these assumptions” to a moral claim turns conviction into equivocation. The opposite is the case.

When I say “slavery is wrong,” Conditionalism unpacks it as: given that we value agency, autonomy, and human flourishing, slavery violates those values and is therefore wrong. That conditional form is stronger, not weaker, because it makes the grounding explicit and debatable. The absolutist version dares an opponent to deny an oracle; the conditional version shows its premises and invites anyone to reject them out loud — and almost no one, pressed in the open, will stand up and reject agency, autonomy, and flourishing. Shared conditions can be adopted, articulated, and defended. They do not need to masquerade as eternal absolutes, and they are more secure for not doing so: a foundation you can inspect is sturdier than one you are forbidden to look at. This preserves exactly what the absolutist rightly refuses to give up — objectivity, the ability to say the slaveholder is wrong and not merely unfashionable — without the incoherent metaphysics. And it preserves what the relativist rightly notices — that all judgment happens inside a framework — without surrendering judgment across frameworks. Objectivity without absolutism; contextual sensitivity without relativism. The most sophisticated modern attempt to secure unconditional moral truths, Parfit’s moral realism, fails by this same diagnosis — its allegedly unconditional truths beg the question by presupposing the very conditions they refuse to state — an argument I make in the near misses.

Shared Conditions

A society cannot survive without common standards, and the fear that abandoning absolutes means abandoning standards is the deepest motive behind absolutism. The fear is misplaced. What a society needs is not absolute truth but shared conditional frameworks — and these turn out to be what our most robust institutions already are.

Logic, mathematics, empirical science, human rights: none of these is unconditional. Each rests on adopted conditions — inference rules, axioms, methodological commitments, a valuation of persons. Their robustness comes not from being condition-free but from their conditions being so widely adopted and so practically indispensable that opting out carries enormous cost. Within our shared vantage they function as if absolute — we do not renegotiate arithmetic at every transaction — while at the meta-level we remain aware that they are conditional. That dual stance is not a compromise; it is the accurate description of how every functioning standard has ever actually worked.

How Far the Conditions Reach

Conditionalism is not only a diagnosis of a philosophical dispute; it is a working method, and the rest of this volume runs on it.

In science, it locates exactly what an experiment tests: never a hypothesis in isolation, but the hypothesis given instruments, auxiliary assumptions, and idealizations — which is why scientific knowledge is permanently revisable without being permanently suspect. In probabilistic reasoning it is even more direct: Bayesian updating simply is conditional reasoning made quantitative, every credence a credence given evidence and background — the framework I defend against its critics in defense of Bayes. And in the Quantum Branching Universe (QBU) — the Everettian picture introduced in Measure and Credence — conditionality reaches into physics itself: claims about events and outcomes hold truth values only relative to a branch, a theme developed in probability without collapse. The pattern repeats at every level. Wherever truth is being evaluated, conditions are doing the work, and progress comes from dragging them into the light.

The Climb

Conditionalism keeps everything worth keeping from the traditional reverence for truth, including its humility. We are biased, error-prone creatures, and we must climb toward better approximations. But the climb is not toward an impossible Absolute; it is the refinement and expansion of our conditional frameworks — stating conditions more precisely, replacing narrow ones with broader ones, discarding frameworks whose conditions cannot survive being made explicit. The climb is real. The progress is measurable. The grounding is honest.

The defence of truth requires rejecting both of its traditional defenders. Relativism must go because it is self-refuting and morally disarming; absolutism must go because it is blind to its own foundations. What remains is not a compromise between them but the position both were failing to articulate: truth as conditional validity relative to explicit assumptions. In a world split between dogmatists and nihilists, conditional truth is the only solid ground.