The Utopia of a modern dreamer must needs differ in one fundamental aspect from the Nowheres and Utopias men planned before Darwin quickened the thought of the world.
Those were all perfect and static States, a balance of happiness won for ever against the forces of unrest and disorder that inhere in things. One beheld a healthy and simple generation enjoying the fruits of the earth in an atmosphere of virtue and happiness, to be followed by other virtuous, happy, and entirely similar generations, until the Gods grew weary.
Change and development were dammed back by invincible dams for ever. But the Modern Utopia must be not static but kinetic, must shape not as a permanent state but as a hopeful stage, leading to a long ascent of stages.
Do not resist
Nowadays we do not resist and overcome the great stream of things, but rather float upon it. We build now not citadels, but ships of state. For one ordered arrangement of citizens rejoicing in an equality of happiness safe and assured to them and their children for ever, we have to plan "a flexible common compromise, in which a perpetually novel succession of individualities may converge most effectually upon a comprehensive onward development."
That is the first, most generalised difference between a Utopia based upon modern conceptions and all the Utopias that were written in the former time.