There are several kinds of brotherhood. First there is professional brotherhood, which is seen in the unionizing of some profession or other. In appearance it is a brotherhood, but in fact the members have become brothers only because of their mutual interest in that profession. One may call them brothers, but they are certainly not twins! They have become brothers for earthly benefit, with the good motive of furthering their particular profession as much as possible. But there is another side to it: that all those who are outside that profession are not brothers; they are only cousins and it would not be wrong to profit by them, and the brothers will meet and find out how best to profit by the cousins. We find this idea in the Mahabharata, the ancient Hindu scripture, where a war is described between brothers and cousins. It is symbolical.