. . . . in order to use a language one has to be part of a community, so when for example we’re describing our inner life, when we’re describing let’s say our dreams, nobody has access to our dreams other than us. But when we’re describing our dreams we use words and those words are words of a public language, and we’ve learned those words in a public context. So I might – you know I might have a dream, okay I might chose not to describe it to anybody in which case it remains private, that’s – that’s perfectly possible. But after all we have a word dream, and that word is a public word, it’s part of a public institution, how did we learn that word? It can’t be that we learnt that word from our own experience and then we applied it to other people that can’t be right. We must have learned it from other people and then applied it to ourselves, the private can’t be prior to the public, the public must be prior to the private. It must be that we are able to describe our dreams and then it’s intelligible that we can have a dream and we don’t describe it
Ray Monk The 2014 Seymour Biography Lecture.