Can another man perceive that I am conscious of anything, when I perceive it not myself?
 John Locke, An Essay Concerning Human Understanding (1689). copy citation

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Author John Locke
Source An Essay Concerning Human Understanding
Topic
Date 1689
Language English
Reference
Note
Weblink http://www.gutenberg.org/files/10615/10615-h/10615-h.htm

Context

“whereas hunger consists in that very sensation, as thinking consists in being conscious that one thinks. If they say that a man is always conscious to himself of thinking, I ask, How they know it? Consciousness is the perception of what passes in a man’s own mind. Can another man perceive that I am conscious of anything, when I perceive it not myself? No man’s knowledge here can go beyond his experience. Wake a man out of a sound sleep, and ask him what he was that moment thinking of. If he himself be conscious of nothing he then thought on, he must be a notable diviner of thoughts that can assure him that he was thinking.” source