Rawls' famously suggests that persons are free and equal by virtue of their having two 'moral powers'. The first is a sense of justice, understand as:
...the capacity to understand, to apply, and to act from the public conception of justice which characterises the fair terms of social cooperation....a sense of justice also expresses a willingness, if not the desire, to act in relation to others on terms that they also can publicly endorse
Essentially this limits our desire for instituting systems which infringe upon each others liberty...i.e. by allowing power to be concentrated in the hands of a few, or instituting discriminatory practices which leave the worst-off in states of abject poverty for the greater glory of the majority.
The second moral power, is the cacpity to have a conception of the good, or:
...the capacity to form, to revise, and to rationally pursue a conception of one's rational advantage or good.
Essentially we can understand how we form these conceptions as the perennial question, commonly asked of young men on the open steppes: "What is best in life?"
In view of Conan's musings, what are we to say about his fitness as an equal and free person, and the tenability of Rawls' political liberalism (on the open steppes, or elsewhere)? Certainly Conan has a conception of the good: crushing enemies, seeing them driven before you, and hearing the lamentations of their women. Tick for Conan.
But would Conan publicly endorse his concept of the good as being reasonable? Obviosuly he thinks it is perfectly reasonable from his current position in the social order (sitting on that lovely throne of his). It is debatable, however, whether he would be as keen for slaughter if he didn't know what his position in the social order would be and whether his conception of the good would include the pleasures of pillage. But he might...indeed much like feudal systems of yore, the worst-off in 'Barbarian' society might be strongly resigned to the divine justice of a might-makes-right philosophy. The justice of death at the hands of Conan might be reasonable and rational...but probably not.
In any case, Conan the Barbarian shouldn't be acting as our representative when formulating the social order - atleast if we want Rawls's version of it. In fact putting Conan in a position of any political power would be an act of collective madness. Only a society so enamoured with the reflected glow of the powerful that it wishes for and actively encourages the accumulation of power and wealth in the hands of a small minority would conceive of such a scheme....