“Social Justice” is a code phrase of the left, which believes that such justice can only be achieved by the recognition that capitalism and the economic inequality it produces must be replaced by a “classless” society wherein all differences in wealth and property have been eliminated. The “Social Justice Movement” (quotation marks are necessary because its version of “justice” is political rather than lexical) is quintessentially deterministic, believing as a core principle that people are what they are because they were born into an inflexible social order.
The “Social Justice Movement” is at war with classical liberalism, which defines equality as the equality of all individuals before the law, irrespective of “class” or any other collective identity. In modern terms, the conflict between these two worldviews is similar to the conflict between “equality of opportunity” and “equality of outcome,” which can only be guaranteed and enforced by some structure of authority.
The “Social Justice Movement” endorses socialism as a means of redressing the alleged evils of capitalism and producing a programmatic equality that it acknowledges will be purchased at the price of individual liberty and require the manufacture of what totalitarian governments have called “the New Man.”