A brain must have space. So what is space? Not only the space between here and there - space indicates 'without a centre'. Right? If you have a centre, and you move away from the centre to the periphery, however long, wide the periphery is, it is still limited. Right? Are we following each other? So, space indicates, does it not, where there is no centre and there is no periphery, there is no boundary. Have we such a brain that one doesn't belong to any thing, attached to anything - attached to one's experience, conclusions, hopes, ideals, and so on, so that the brain is really, completely free? Right? If it is burdened, you can't walk very far, you can't go very far. If it is crude, vulgar, self-centred, it cannot have measureless space. And space indicates - one is using the word very, very carefully - emptiness. Are you following? Does it interest you at all this? Are you sure, coming here in spite of the awful rain and wind, we are communicating with each other?