Question

who among the political thinkers made both 'the need' as well as 'merit'the basis on which he framed his theory of justice​

Answer 1

Rawls calls this the capacity for a conception of the good. Together these capacities are called the two moral powers. Like every theory of justice (for example those of Locke, Rousseau and Mill), justice as fairness requires an account of citizens' fundamental interests: what citizens need qua citizens.