While perhaps too broad and interspersed with too many amusing asides, the foregoing description of how we arrive at mutual understanding and at the insight that ‘we all live in the same world’ must, it seems to me, be accepted as factual even by those who regard it as an eccentric whim to wish to deny ‘reality’ to this world that we have in common. If you will grant me that description, I will not quarrel over ‘reality’, at least not until I have to. ‘Reality’, ‘existence’ and so forth are empty words. All that matters to me is this: suppose you do see it as necessary to refer the broadly shared character of one part of our experience (the part we call external) to the idea that the same die applied to similar ‘malleable surfaces’ will tend to produce similar structures, you still ought not to suppose that this can either explain or guarantee our awareness of this shared character. If you suppose that there is a real external world which is the active cause of sensation and which can consequently be influenced by our voluntary actions (an idea which I recommend you to avoid), then the danger arises of going on from this plausible explanation of our common experience to regarding our knowledge of it as obvious, inevitable and complete, and to stop being concerned about its origin or the degree of completeness to which it can attain. To do so is simply wrong; this is no mere dispute over words.