d in four arguments: the parity; master; substratum and dependency arguments. The parity argument states that primary and secondary qualities are perceived the same way and that neither of them exists without the perceiver. The implication of this argument is that everyone can perceive things differently, depending on their views and past experiences. Locke states in his "Common World Objection," that if idealism is true and physical objects are ideas, i.e. private to the individual, one can never see the world the same as someone else. But, we know that many of us see things very similarly, so idealis
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