What does it mean for a property to exist? Why do scientific laws hold? What makes a statement true? And what, exactly, must exist for our best theories about the world to work? This book offers a clear, engaging, and intellectually sharp guide to the philosophy of David Malet Armstrong, one of the most influential metaphysicians of the twentieth century. Known for defending realism about universals, developing the modern theory of truthmakers, and arguing that metaphysics should take science seriously, Armstrong built a systematic vision of reality that continues to shape contemporary debates in philosophy. Written in accessible language without sacrificing philosophical precision, this volume explains Armstrong’s key ideas step by step: universals and properties, the instantiation relation, states of affairs, laws of nature, modality, truthmakers, and the structure of scientific explanation. Major works are examined in context, core arguments are reconstructed in straightforward terms, and competing views—nominalism, trope theory, Humean accounts of laws, dispositional essentialism, structural realism, and modal realism—are compared and critically evaluated. The book also explores Armstrong’s intellectual influences, the revival of metaphysics in the late twentieth century, the development of the truthmaker movement, and the continuing impact of his ideas on current philosophical research. Along the way, it shows how Armstrong’s central methodological question—What must exist for our best theories to be true?—remains one of the most powerful guiding principles in contemporary philosophy.
