Can the physical world be explained without relying on abstract, non-physical objects?

Ideas & Philosophy · Published 3 October 2026 Swipe more like this →

In short: David Malet Armstrong argued that reality is strictly physical, rejecting Platonic forms in favor of a sparse system of universals. By grounding laws of nature in the relationships between these physical properties, he sought to build a comprehensive, scientific metaphysics that accounts for everything that exists within space and time.

David Malet Armstrong, a prominent Australian philosopher who taught at the University of Sydney for nearly three decades, championed a naturalistic worldview. His philosophy was built on the fundamental assumption that the physical, space-time world is all that exists. This stance led him to reject abstract objects, such as Platonic forms, which he viewed as unnecessary and hypothetical. Instead, he proposed a 'sparse' ontology where universals—properties like mass—are only recognized if they are deemed essential by scientific investigation.

Central to his system is the concept of 'states of affairs,' which he identified as the fundamental structures of reality. Armstrong argued that these states, which involve a particular instantiating a universal, are necessary to explain truth and falsity. For instance, he maintained that relations between particulars are not merely sums of their parts; they require states of affairs to account for non-symmetric interactions. This framework also provided the basis for his account of laws of nature, which he viewed as relations between universals rather than mere descriptions of how we talk about the world.

Armstrong was also a key figure in the philosophy of mind, defending a 'central-state' theory that identified mental states with physical states of the nervous system. His work in epistemology was similarly grounded in externalism, comparing the reliability of human belief to a thermometer tracking environmental temperature. Throughout his career, which included service in the Royal Australian Navy and academic appointments from 1954 until his 1991 retirement, Armstrong remained committed to a philosophy that was ontically economical and continuous with the natural sciences, famously advising peers to 'put semantics last' when settling ontological questions.

General information, not professional advice. Spotted an error? Flag the card or see corrections and complaints.

Intellect Plus is a visual educational discovery platform for exploring fascinating facts and ideas. Brain Food, Not Brain Rot. What is Intellect Plus?

Related

• Is the physical world an objective reality or a mental construct?
• Is the physical world merely a projection of the human mind?
• Why the world is not a collection of things, but a series of events.
• Is the universe a physical object or a mathematical structure?
• Did the Gospels record history, or did they craft a powerful, legendary myth?
• Can a single law of association explain the entire human experience?
• Who was David the Invincible, the 6th-century philosopher shrouded in medieval legend?
• Why does the feeling of being alive exist, and can science explain it?
• How a mouse on a temple idol sparked a revolution in Indian religious thought
• Is coming into existence a fundamental harm? A philosopher argues we should not procreate.
• Was Debendranath Tagore the bridge between ancient Hindu tradition and modern social reform?
• Dasein: Why Martin Heidegger believed human existence is a constant, urgent philosophical question

More in Philosophers · More in Ideas & Philosophy · Latest · A–Z · All topics