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Ontology and the Question of Existence

A Clear Introduction to Being, Reality, and What It Means to Exist

What does it mean to exist?

Ontology and the Question of Existence offers a clear and accessible introduction to one of philosophy’s oldest and most fundamental fields. Beginning with ordinary objects and everyday language, it explores the deeper questions hidden beneath familiar assumptions: What kinds of things are real? Are properties, numbers, events, institutions, minds, and fictional characters genuine parts of reality? What makes something remain the same through change? Can absences, possibilities, or digital objects exist?

Drawing on thinkers from Aristotle and René Descartes to Saul Kripke, David Lewis, Kit Fine, Sally Haslanger, and contemporary philosophers of mind, society, mathematics, and technology, the book explains major ontological theories without assuming previous philosophical training. Difficult ideas such as substance, universals, grounding, possible worlds, personal identity, consciousness, social construction, and artificial agency are introduced through concrete examples and precise arguments.

The discussion also shows why ontology matters beyond academic philosophy. Questions about what exists now shape debates involving artificial intelligence, digital ownership, institutional responsibility, social categories, modern physics, personhood, and the status of increasingly complex technological systems.

Author
Quim Aiguafreda
Published
July 17, 2026
Pages
229
Language
English
ISBN
979-8187770847

From the opening pages

You probably believe that chairs exist. This is not yet a philosophical achievement. You sit on them, trip over them, and occasionally assemble them incorrectly while insisting that the manufacturer supplied the wrong screws. Chairs belong to the part of reality that rarely needs defending.

But consider a hole in a chair. Does the hole exist? It can be measured, described, enlarged, and blamed for the chair’s collapse. Yet it appears to be made of precisely nothing. Consider the number seven. It is not located inside any of the seven objects it counts. It has no weight, colour, temperature, or known postal address, but mathematics would become noticeably inconvenient without it. Consider the government, a debt, a promise, a fictional detective, a computer file, or the possibility that you might have chosen a different chair. All of these can be discussed meaningfully. Some can affect your life with impressive efficiency. It does not follow that they all exist in the same way.

Ontology begins with three connected questions: what exists, what kinds of things exist, and what it means to say that something exists. These questions sound simple because the word “exists” is familiar. So are the words “time,” “person,” and “money,” and none has rewarded confidence with clarity.

Contents

8 chapters

  1. Orientation

    • What Ontology Asks
    • Ontology and Metaphysics
    • A Brief History of Being
  2. What Is a Thing?

    • Objects and Properties
    • Substance
    • Universals
    • Particulars
    • Relations
    • Facts
    • Events and Processes
  3. What Does It Mean to Exist?

    • Is Existence a Property?
    • Being and Beings
    • Quine’s Inventory
    • Ontological Commitment
    • When Grammar Misleads Us
    • Ontological Parsimony
    • One Existence or Several?
    • Fundamental and Dependent Reality
  4. Parts, Wholes, and Identity

    • Parts and Wholes
    • When Do Parts Form a Thing?
    • Are There Really Tables?
    • The Special Composition Question
    • The Ship of Theseus
    • Persistence Through Time
    • Essential Properties
    • Natural Kinds
    • Vagueness
  5. Time

    • What Exists in Time?
    • Does the Past Exist?
    • Does the Future Exist?
    • Does Time Pass?
    • Beginnings and Endings
  6. Abstract, Possible, and Absent Things

    • Numbers
    • Sets and Structures
    • Possibility and Necessity
    • Possible Worlds
    • Impossible Objects
    • Nothing, Absence, and Holes
  7. Minds and Constructed Reality

    • Minds and Consciousness
    • Personal Identity
    • Copies, Societies, and Artificial Agents
  8. Ontology Now

    • Contemporary Ontologists
    • Why Ontology Matters Now