First, if we really didn’t know who we would be, we would want to protect our “basic liberties”, including personal freedoms such as freedom of speech, religion and sexuality, but also the political freedoms we need to play a genuinely equal part in collective decision-making.
Second, in addition to ensuring “fair equality of opportunity”, we would want to organise our economy so that the least well off are better off than under any alternative system (Rawls called this the “difference principle”). From this perspective, higher pay for some can be justified as an incentive to work, study or innovate, but only if this ultimately ends up benefiting those who have less – not just by a little, but as much as possible.
That’s therefore classical liberalism – Hayek and Friedman all over again. It’s not that there’s anything wrong with it, it’s just what the fuck is new with it?