Their intellectual imperialism invades every field and pervades everything and, as their forebearers (such as Walter Rauchenbush, author of “Christianizing the Social Order,”) they would create the most comprehensive theocracy ever. And yet they think their dogma is nothing but the product of pure reason and disinterested social science.
Understanding the underlaying premises that lead many of these to assert & believe that “social justice” is arrived at through sound “social science” will be a good step for boulstering your own arguments. I.E. Rawls (which not all of these people cite explicitly as an underlaying source, but almost all of them are influenced by it) based his “Theory of Justice” essentially on Welfare Economics as derived from Neoclassical assumptions.
So reading or listening to Austrian Critiques & explainations of the differences and what is wrong with this approach is helpful (here is a great video by Bob Murphy doing that).
Also knowing the roots & origins of social justice and the uplift generally and how, rather than being an “optimistic view of human nature,” it is one that believes in manipulation of people by a cadre of experts will be helpful. While many social scientists, deep in their heart, want to be manipulators (that’s what The [Social] Uplift is all about), not many of their targets (which include their student-audiences) want to be the manipulated.
Understanding that all of this implies not egalitarian equality in the least, but rather a permanent caste structure between the technocratic manipulators and the mass which is molded will help as well.
Mostly, knowing and showing just how much all the things they advocate ruin rather than help lives, kill rather than save lives, produce rather than reduce inequality, and the like will be very helpful. For better or worse, you do also have to appeal to people’s emotions and the fact that if you want to help people, you certainly don’t ruin their lives for them. (Much of Progressivism is based on people wanting to feel better about themselves and then displacing blame for the bads their policies produce).
Also, and a lot of free-marketeers get this wrong when they speak only of incentives and perverse incentives, and fail to explicitly connect why people react the way they do when incentives are distorted: because of the injustice that is being done. Progressive egalitarian “social justice” schemes fail (in part) because they inflict injustice in the name of justice.
Hitting people with the Mises arguments about calculation problems and the dynamics of interventionism is important, but to that really does need to be added one’s sense of justice, and how these schemes are peverse not simply because they won’t produce what the activists want, but they are unjust in-and-of-themselves.
Also I’ll add something: don’t expect to win over everyone and certainly you won’t have the amount of time professors have. Sometimes the best thing to do is an incisive polite-but-puncturing comment, correctly time, that doesn’t attempt to rebut an entire lecture but will cause students – at least ones who want to think more – to realize that there is more to things than they are being presented with, and indeed what they are being presented with are caracatures and tendentiously mendacious distortions. Until you’re outside of class (whether talking to these very same fellow students at the student union or whether discussing things with random other people by some other means), you’re up against a machine too strong.
But the more knowlegable you are yourself across as wide a variety of subjects as possible and thus can speak intelligently and from a position of superior information, the easier it will be to plant these seeds of doubt. Which is about all you can do as a student in a class; plant seeds of doubt in the mind of fellow students, and show that the opposition to The Narrative is not the side that is misinformed or ignorant; rather, it is “The Cathedral” (the social-justice-progressive-education-media-statist-complex) that is a font of ignorant misinformation.
Read all their stuff, and all the stuff by the professors here and the scholars at the Mises Institute that you can, watch all the videos, follow as many footnotes as you can. Intellectually arm yourself.
Basically there is no shortcut: one has to be an autodidact and a polymath.