“Two normal observers viewing the same object from the same place under the same physical circumstances do not necessarily have identical visual experiences, even though the images on their respective retinas may be virtually identical.”

— Alan Chalmers, book What Is This Thing Called Science?

Source: What Is This Thing Called Science? (Third Edition; 1999), Chapter 1, Science as knowledge derived form the facts of experience, p. 5.

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Alan Chalmers17

Australian philosopher of science 1939

Alan Chalmers book What Is This Thing Called Science?

Source: What Is This Thing Called Science? (Third Edition; 1999), Chapter 1, Science as knowledge derived form the facts of experience, p. 8.

“Still, for the first time in our lives, we would have been through exactly the same experience, from exactly the same point of view -- even if the experience was only spending eight hours locked in separate rooms, and the point of view was that of a genderless robot with an identity crisis.”

Greg Egan (1961) Australian science fiction writer and former computer programmer

Closer
Fiction, Axiomatic (1995)

“A big advantage of the serial-number approach to identity is that things stay the same even as they change.”

Brian Hayes (scientist) (1900) American scientist, columnist and author

Source: Group Theory in the Bedroom (2008), Chapter 11, Identity Crisis, p. 213

“Logic tends to reduce everything to identities and genera, to each representation having no more than one self-same content in whatever place, time or relation it may occur to us. And there is nothing that remains for two successive moments of its existence.”

Miguel de Unamuno (1864–1936) 19th-20th century Spanish writer and philosopher

The Tragic Sense of Life (1913), V : The Rationalist Dissolution
Context: A terrible thing is intelligence. It tends to death as memory tends to stability. The living, the absolutely unstable, the absolutely individual, is strictly unintelligible. Logic tends to reduce everything to identities and genera, to each representation having no more than one self-same content in whatever place, time or relation it may occur to us. And there is nothing that remains for two successive moments of its existence. My idea of God is different each time that I conceive it. Identity, which is death, is the goal of the intellect. The mind seeks what is dead, for what is living escapes it; it seeks to congeal the flowing stream in blocks of ice; it seeks to arrest it. In order to analyze a body it is necessary to extenuate or destroy it. In order to understand anything it is necessary to kill it, to lay it out rigid in the mind.