These lines from BR Ambedkar from Annihilation of Caste on the concept of Equality, are an absolute must-read.
First, he classifies equality along three dimensions:
Equality may be a fiction but nonetheless one must accept it as the governing principle. A man’s power is dependent upon (1) physical heredity, (2) social inheritance or endowment in the form of parental care, education, accumulation of scientific knowledge, everything which enables him to be more efficient than the savage, and finally, (3) on his own efforts. In all these three respects men are undoubtedly unequal. But the question is, shall we treat them as unequal because they are unequal ? This is a question which the opponents of equality must answer. From the standpoint of the individualist it may be just to treat men unequally so far as their efforts are unequal. It may be desirable to give as much incentive as possible to the full development of every one’s powers. But what would happen if men were treated unequally as they are, in the first two respects ? It is obvious that those individuals also in whose favour there is birth, education, family name, business connections and inherited wealth would be selected in the race. But selection under such circumstances would not be a selection of the able. It would be the selection of the privileged. The reason therefore, which forces that in the third respect we should treat men unequally demands that in the first two respects we should treat men as equally as possible.
Assuming this three-fold classification of (in)equality, one can deduce what Ambedkar would have said about the contemporary demands for reservation. He would have opposed them as the groups seeking affirmative action are not disadvantaged in the first two respects. If anything, some of these groups have been the most dominant political communities in the states.
Ambedkar then gives a utilitarian reason for why we need to uphold the principle of equality.
On the other hand it can be urged that if it is good for the social body to get the most out of its members, it can get most out of them only by making them equal as far as possible at the very start of the race. That is one reason why we cannot escape equality. But there is another reason why we must accept equality. A Statesman is concerned with vast numbers of people. He has neither the time nor the knowledge to draw fine distinctions and to treat each equitably i.e. according to need or according to capacity. However desirable or reasonable an equitable treatment of men may be, humanity is not capable of assortment and classification. The statesman, therefore, must follow some rough and ready rule and that rough and ready rule is to treat all men alike not because they are alike but because classification and assortment is impossible. The doctrine of equality is glaringly fallacious but taking all in all it is the only way a statesman can proceed in politics which is a severely practical affair and which demands a severely practical test.