Individual rights function as near-absolute side constraints

Nozick's foundational move is treating individual rights not as goals to be maximized or balanced against other social goods, but as boundaries that action may not cross regardless of the benefits that crossing them might produce. You cannot justifiably violate one person's rights even to produce a greater aggregate benefit for many others, because rights function as constraints on permissible means, not as one value among many to be weighed.

This directly opposes utilitarian reasoning, which would permit rights violations whenever the resulting benefits outweigh the costs in aggregate. Nozick argues this kind of trade-off treats individuals as interchangeable resources for producing social good, rather than as separate persons each entitled to their own life and choices.

This framework does most of the argumentative work in the rest of the book: if rights are genuinely near-absolute side constraints, then redistribution that takes from one person without consent to benefit others becomes suspect by definition, however good the resulting outcome looks in aggregate. Rights aren't one weight on the scale — they're limits on what's allowed on the scale at all.