Problem of the Many

Overview and Classic Formulation

The Problem of the Many is a paradox in metaphysics and the philosophy of language concerning vagueness, material objects, and reference. It was most famously developed by Peter Unger in his 1980 paper The Problem of the Many, though it draws on earlier worries about vague boundaries, such as those raised by the Sorites paradox.

The standard example involves a cloud. Intuitively, there is one cloud in the sky. Yet at the cloud’s edges are many “borderline” droplets of water vapor: it is unclear whether each such droplet is part of the cloud or not. For every borderline droplet, we can construct a slightly different collection of droplets that is still cloud-shaped and still satisfies our ordinary criteria for being the cloud. Thus there are many overlapping candidate clouds, each almost identical to the others, differing only in the inclusion or exclusion of a few marginal droplets.

Each of these candidate aggregates seems to be:

• large and cloud-shaped,
• meteorologically significant,
• the kind of thing that can rain or cast a shadow.

Yet we normally speak as if there is just one cloud. The paradox is that:

• either there are many clouds where we thought there was one,
• or none of the candidate aggregates is the cloud,
• or we must radically revise our understanding of vagueness, existence, or reference.

The problem generalizes easily to persons, cats, mountains, and other ordinary objects: in each case, multiple overlapping collections of particles appear to be equally good candidates for being that very object.

Philosophical Significance

The Problem of the Many is significant because it brings together and pressures several core areas of philosophy:

1. Metaphysics of Material Objects
   The paradox challenges assumptions about what objects there are and how they are constituted by their parts (their mereology). It raises questions such as:

   • When do some particles compose an object?
   • Can many distinct objects occupy almost exactly the same region of space?
   • Are ordinary objects “vague” in their existence and boundaries?

2. Vagueness and Ontology
   Unlike purely linguistic puzzles about vague terms, the Problem of the Many suggests that vagueness might be in the world itself, not merely in our language. The marginal droplets or hairs seem to make the object’s boundary vague, not just the word “cloud” or “person.”

3. Philosophy of Language and Reference
   The paradox also concerns how words latch onto things in the world. If there are many cloud-candidates, which one does the word “that cloud” pick out? The problem pressures theories of:

   • definite descriptions and demonstratives (“that cloud”),
   • singular reference (how language targets one object among many),
   • semantic theories of vagueness (e.g., epistemicism, supervaluationism).

Because it straddles metaphysics and semantics, the Problem of the Many serves as a test case for comprehensive theories of vague objects and vague talk.

Main Responses

Philosophers have offered several major styles of response. None commands universal acceptance, and each is associated with distinctive revisions to our views about objects or language.

1. Many-Objects (or “Abundant Clouds”) View

On this response, there really are many clouds in the problematic situation. Every eligible collection of droplets that fits the “cloud role” is genuinely a distinct cloud, all almost perfectly overlapping.

• Motivation:
  This view respects the intuition that each candidate aggregate satisfies the conditions for being a cloud; instead of arbitrarily choosing one, it accepts them all.

• Costs:
  It conflicts with everyday thought, which treats there as being one cloud, not dozens or thousands. It also raises questions about how to count and refer to objects in scientific and ordinary contexts.

Some proponents attempt to soften the counterintuitiveness by explaining why we reasonably speak as if there is “one” cloud, perhaps because the overlapping clouds behave as a single macroscopic system.

2. No-Object (or “Eliminativist”) Views

Another response denies that there is any precise cloud-object corresponding to our ordinary talk. On such views, there may be:

• fundamental particles or fields,
• but no sharp, well-defined composite object that is the cloud.

Ordinary talk of “the cloud” is then treated as a useful fiction, a way of describing complex arrangements of more fundamental entities.

• Motivation:
  This avoids the need to choose among or multiply cloud-candidates.

• Costs:
  It is highly revisionary about the existence of ordinary objects and can be difficult to reconcile with the apparent reality of mid-sized physical objects in everyday and scientific discourse.

3. Sharp-Boundary or Epistemicist Views

Epistemicism about vagueness holds that boundaries are in fact sharp, but we cannot know exactly where they lie. Applied to the Problem of the Many, epistemicists maintain:

• there is exactly one correct cloud-candidate,
• but our epistemic limitations prevent us from knowing which aggregate it is.

On this view, the vagueness is in our knowledge, not in the world itself.

• Motivation:
  It preserves a classical, bivalent metaphysics: each droplet either is or is not part of the cloud, and there is a uniquely correct cloud.

• Costs:
  Critics object that this makes the sharp boundary metaphysically “mysterious” and deeply unintuitive, since no underlying physical or functional difference appears at the boundary.

4. Supervaluationist and Semantic Approaches

Supervaluationism treats vagueness as a feature of language. There are many admissible “precisifications” of vague terms like “cloud.” An utterance is:

• supertrue if it is true on all precisifications,
• superfalse if false on all,
• otherwise has an intermediate status.

Applied here, a defender might say:

• there are many admissible ways of making “cloud” precise, each corresponding to a different candidate aggregate,
• but ordinary claims like “There is a cloud in the sky” can still be supertrue, because on every admissible precisification at least one candidate is a cloud.

This allows one to say that there is one cloud in an ordinary sense, without needing to designate a single metaphysically privileged aggregate.

• Motivation:
  It avoids both mass multiplication of objects and eliminativism, and it keeps the ontology closer to common sense.

• Costs:
  Some argue that it dodges the ontological question: even if semantics is handled, which aggregate (if any) is the cloud in reality remains obscure.

5. Pragmatic and Contextualist Strategies

Other approaches emphasize context or pragmatic factors. On these views, which candidate aggregate counts as “the cloud” can shift with conversational aims or practical interests. The object we refer to is partly fixed by:

• what features are salient,
• what explanatory or predictive tasks we have,
• what counting or tracking practices are in play.

These strategies often combine with one of the other main theories, attempting to explain how ordinary singular reference works despite the underlying metaphysical messiness.

Across these responses, the Problem of the Many continues to function as a central puzzle. It tests how well theories of vagueness, composition, and reference can accommodate our intuition that there is “one cloud” or “one person,” even when the world seems to supply many overlapping candidates or none at all.