Before revision: Bertrand Russell among others believed the problem is Berkeley's argument "seems to depend for its plausibility upon confusing the thing apprehended with the act of apprehension":Bertrand Russell, The Problems of Philosophy, pages 22 to 23.
After revision: Bertrand Russell among others believed Berkeley's argument "seems to depend for its plausibility upon confusing the thing apprehended with the act of apprehension":Bertrand Russell, The Problems of Philosophy, pages 22 to 23.