Introduction
The Latin phrase “Esse est percipi”, meaning “To be is to be perceived,” is famously associated with the Irish philosopher George Berkeley. This idea lies at the heart of his idealist philosophy, which denies the existence of material substances independent of perception. According to Berkeley, the existence of objects depends entirely on their being perceived by a mind.
Berkeley’s Idealism
Berkeley challenged the materialist notion that physical objects exist outside of consciousness. He argued that all that we know are sensory experiences — colors, sounds, textures — which exist only in the mind. Therefore, there is no reason to believe in a world beyond perception.
In Berkeley’s view, an apple exists because it is seen, touched, or smelled. When it is not being perceived by a human, it continues to exist because it is perceived by God, the ultimate perceiver. Thus, God guarantees the consistency and continuity of the world.
Implications and Criticism
This idea challenges common sense realism and has been criticized for leading to solipsism — the belief that only one’s own mind is certain to exist. Critics also argue that it undermines scientific inquiry, which assumes an external, observer-independent world.
Conclusion
Despite criticisms, “Esse est percipi” remains a provocative and influential idea in epistemology and metaphysics. It highlights the central role of perception in constituting reality and invites ongoing reflection on the relationship between mind and world.