From Herbert Spencer who’s Social Statics has rocked my world far later in life than I would have wished had. But hindsight is 20/20.
The greatest happiness (utopia) is desired.
What satisfies desire is the employment of faculties (human powers).
The employment of human faculties requires freedom.
Thus, freedom is essential for the production of utopia.
The greatest happiness can be nothing more than the combination of individual happinesses (the greatest being found nowhere but in the sum of the individuals).
Thus, the maximization of liberty until it trespasses another’s liberty. This is the fundamental principle of utopia. To begin to an assault on other’s bodies or other property rightfully theirs is to limit the possibility of utopia from the outset.