Why we do not perceive an objective reality, but construct our own

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

In short: We often assume our minds act like cameras, capturing a true image of the world. But according to the philosopher Ernst von Glasersfeld, our knowledge is not a reflection of an external reality, but a personal construction. Discover the radical theory that challenges the very foundation of human perception.

Ernst von Glasersfeld (1917–2010) was a central figure in the development of radical constructivism, a theory that fundamentally reinterprets the relationship between the mind and the external world. Rather than viewing cognition as a process of discovering pre-existing truths, Glasersfeld argued that knowledge is actively constructed by the individual. This perspective draws on a diverse lineage of thought, including Jean Piaget’s genetic epistemology, the perception theories of Bishop Berkeley, and even the linguistic complexities of James Joyce’s Finnegans Wake.

The roots of Glaserspecfeld's life were as complex as his theories. Born in Munich, his family's Pan-European identity and his grandfather's Jewish heritage forced him to flee the University of Vienna due to the Nazi threat. His subsequent journey through Ireland, Italy, and eventually the United States allowed him to collaborate with thinkers like Silvio Ceccato and contribute to various intellectual disciplines, including the creation of the artificial language Yerkish.

Radical constructivism posits that because we cannot step outside our own cognitive processes to verify an 'objective' world, we must focus on how our experiences are organized. This approach has had profound implications for science, teaching, and cybernetics. His contributions were recognized globally through numerous honors, such as the 1991 McCulloch Memorial Award and the 2005 Gregory Bateson Award. Today, his intellectual legacy is preserved in the Ernst von Glasersfeld Archive at the University of Innsbruck, ensuring that his challenge to the concept of objective truth continues to influence modern systemic research.

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