The proposition that “only things observed exist” challenges our conventional understanding of reality. This concept has been a subject of philosophical debate for centuries and finds resonance in certain interpretations of modern physics. Let’s delve into the philosophical roots of this idea and its implications.

George Berkeley’s Subjective Idealism

In the 18th century, Irish philosopher George Berkeley introduced the doctrine of subjective idealism, asserting that existence is fundamentally tied to perception. Berkeley’s famous dictum, esse est percipi (“to be is to be perceived”), encapsulates his belief that objects only exist insofar as they are perceived by a mind.

Berkeley argued that what we consider physical objects are merely collections of sensory experiences or ideas. For instance, a tree’s greenness, texture, and shape are all perceptions in the mind. If no one perceives the tree, does it still exist? Berkeley would contend that it does not, unless it is perceived by some mind.​

To address the continuity of existence when no human observer is present, Berkeley invoked the omnipresence of God. He posited that God’s constant perception ensures the persistence of all objects, maintaining their existence even in the absence of human observers.​

Quantum Mechanics and the Role of Observation

In the realm of physics, particularly quantum mechanics, the act of observation plays a crucial role in determining the state of a system. The famous double-slit experiment demonstrates that particles like electrons exhibit different behaviors depending on whether they are observed. When unobserved, they display wave-like interference patterns; when observed, they behave like particles.​

This phenomenon has led to interpretations suggesting that observation affects reality at the quantum level. Some physicists argue that particles exist in a superposition of states until measured, at which point the wave function collapses into a definite state .

However, it’s essential to note that this does not imply that macroscopic objects cease to exist when unobserved. The quantum effects are significant at microscopic scales, and their implications for everyday objects remain a topic of debate.​

Philosophical Implications and Criticisms

The idea that unobserved entities do not exist raises several philosophical questions. If existence depends on perception, what happens to objects when no one is observing them? Berkeley’s answer involves divine perception, but this introduces theological assumptions that not all accept.​

Critics argue that this perspective leads to solipsism—the belief that only one’s mind is sure to exist. Such a view challenges the objective reality of the external world and other minds, leading to skepticism about shared experiences and scientific observations .​Wikipedia

Conclusion

The assertion that “only things observed exist” invites us to reconsider the nature of reality and the role of perception. While Berkeley’s philosophical idealism and certain interpretations of quantum mechanics suggest a deep connection between observation and existence, these ideas remain controversial and subject to ongoing debate. Ultimately, this exploration underscores the complexity of defining reality and the enduring interplay between observation, perception, and existence.