Although unconscious of their moral, religious and political commitments, each individual would know they had some, which they would be unlikely to willingly abandon if required to by the state. Similarly, such people could not honour a promise to accept poverty if it happened to be that lower life chances for the few were required to guarantee better chances for the many. The only set of principles capable of acceptance in this original position would be to safeguard the interests of the worst off in society - so inequalities in wealth and power can only exist when the worst off group would be even more impoverished if such inequalities were diminished. So the difference principle says that treating people unequally is only justifiable if by doing so, the least advantaged member of society is made better off.
Citizens are enabled with 2 moral powers. One is the capacity to be reasonable - to have a sense of justice and honour fair in the terms of social co-operation. The other is to have a conception of the good, and the ability to rationally pursue the notion of a good life. These moral powers are for Rawls the deciding factor which means that those in the original position would not choose socio-economic goods over basic liberties - they come to realise higher order interests and thus the question of whether the principle is fair to the talented and productive members of society is irrelevant.
Daniels (1975) does point out incompatibilities in Rawl’s duo of principles. ‘If inequalities permitted by the second principle are very small thus Rawls priority of liberty allows both the wealthy and the poor to possess universal suffrage and identical voting rights, yet socio-economic inequalities allowed in the difference principle mean that in reality there will be limitations. Clearly the wealthy can influence the political outcome more effectively than the poor, with better abilities to influence the political outcome more effectively than the poor, with better abilities to influence public opinion and elected officials. Although possessing equal liberty to participate in the political process, the socio-economic differences means the worst off are unable to effectively exercise this liberty. Consider that there are combined effects - If I am in an advantageous position, where I can influence the political process in a local election, I may be able to gain greater influence over the school of my child, and its organisation. If I owned a newspaper, the combined effects would be to give me much more freedom of expression and influence than those worse in society.
However Rawl’s answers that these socio-economic factors affect only inequalities in the worth of liberty - the ability to exercise it - not liberty itself. Now Rawl’s 2nd principle in allowing socio-economic inequalities, gives unequal value to the liberties of citizens. Yet it also maximises such primary, socio-economic goods to the worst off, so gives their liberties greater value than they would otherwise have.
Thus the talented and productive are still able to wield the tools to improve their already privileged position, whilst simultaneously recognising that the position of the worst-off members of society is better than it would have been previously.