their existence in other classes was derivative. After what I have said regarding the rôle of imitation in the spread of these customs among the non-Brahman castes, as means or as ideals, though the imitators have not been aware of it, they exist among them as derivatives; and, if they are derived, there must have been prevalent one original caste that was high enough to have served as a pattern for the rest. But in a theocratic society, who could be the pattern but the servant of God? This completes the story of those that were weak enough to close their doors. Let us now see how others were closed in as a result of being closed out. This I call the mechanistic process of the formation of caste. It is mechanistic because it is inevitable. That this line of approach, as well as the psychological one, to the explanation of the subject has escaped my predecessors is entirely due to the fact that they have conceived Caste as a unit by itself and not as one within a System of Caste. The result of this oversight or lack of sight has been very detrimental to the proper understanding of the subject matter and therefore its correct explanation. I will proceed to offer my own explanation by making one remark which I will urge you to bear constantly in mind. It is this: that *caste in the singular number is an unreality*. *Castes exist only in the plural number*. There is no such thing as _a_ caste: there are always castes. To illustrate my meaning: while making themselves into a caste, the Brahmans, by virtue of this, created a non-Brahman caste; or, to express it in my own way, while closing themselves in they closed others out. I will clear my point by taking another illustration. Take India as a whole with its various communities designated by the various creeds to which they owe allegiance, to wit, the Hindus, Muhammadans, Jews, Christians and Parsis. Now, barring the Hindus, the rest within themselves are non-caste communities. But with respect to each other they are castes. Again, if the first four enclose themselves, the Parsis are directly closed out, but are indirectly closed in. Symbolically, if group A. wants to be endogamous, group B. has to be so by sheer force of circumstances.