These general considerations should prohibit the putting of quite a lot of wrong questions, but we should be careful to notice what they permit as well as to notice what they prohibit.

Let us, for instance, consider the esse-percipi formula. "To be" does not mean "to be perceived", but if we say, with Berkeley, that "to be a sound is to be heard", "to be an odour is to be smelt", "to be a pleasure is to be felt", our statements (as I said in a former lectureI ) may very well be true, not because "to be" means "to be perceived", but because the sort of thing that is a sound must be something that is heard, and generally because (as some think) all sensations are mentities. Thus it may very well be true that wherever you can say "There is a sound" you are also saying, and mean to say, "Someone is hearing." In a broader way it is possihle that although the words "There is" mean neither more nor less than simply "there is", it is true, nevertheless, that everything that exists has certain common properties although existence is not a "property" in that sense of "property". If so, although it would be false to say that existence implies the common properties that all existents possess,

it would be true to say that these properties are present wherever anything exists.