Well, God has arrived. I met him on the 5.15 train ~ Keynes - Ludwig Wittgenstein

The idea that in order to get clear about the meaning of a general term one had to find the common element in all its applications has shackled philosophical investigation; for it has not only led to no result, but also made the philosopher dismiss as irrelevant the concrete cases, which alone could have helped him understand the usage of the general term.

The sense of a truth-function of p is a function of the sense of p. Denial, logical addition, logical multiplication, etc. etc., are operations. (Denial reverses the sense of a proposition.)

We regard the photograph, the picture on our wall, as the object itself (the man, landscape, and so on) depicted there. This need not have been so. We could easily imagine people who did not have this relation to such pictures. Who, for example, would be repelled by photographs, because a face without color and even perhaps a face in reduced proportions struck them as inhuman.