Types of utopian thinking

There's an interesting discussion of contrasting approaches to utopia in this review of Picture Imperfect: Utopian Thought for an Anti-Utopian Age by Russell Jacoby. According to the reviewer, Jacoby is critical of 'blueprint Utopians'; by being overly prescriptive about what a future ideal society would look like they contradict the dream of freedom:

For Jacoby, the essence of Utopianism is "iconoclasm," rooted in the biblical commandment against uttering the name of God or making graven images of God. "Ye shall make no idols nor graven image" (Lev.26:1). This injunction against representation of the unknown, articulated by Maimonides, was a way of resisting the modern tendency toward visualization. This legacy had a strong influence on the work of Karl Marx, Theodor Adorno, Walter Benjamin, Ernst Bloch, and especially Martin Buber and Gerson Scholem whose work resurrected the Kabala, the mystical tradition in Judaism, and Gustav Landauer, a messianic Utopian who refused to spell out the details of what that Utopia might look like...
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The protestors and breakers of images would have us "hear" the future but not see it - lest any concrete depiction stifle what might more imaginatively be. Jacoby argues that "iconoclastic utopians" foster a political imagination that offers genuine hope and possibility rather than the puritanical order of "blueprint" Utopians... The iconoclastic tradition is critical of existing social arrangements, especially those that sustain domination, fragment the social and thwart human development and freedom... [It is] more likely to spell out what is wrong with the current world than offer any kind of picture of what a future world might look like. They reject icons.

But there's a problem here. Utopias of the free imagination - the iconoclastic tradition - remain indispensable. They break through the limited understanding of possibility that grows out of the world as it is. For this world, in some respects one of constraints that are unchangeable and unavoidable, is also a historical and cultural world; some of its constraints only appear to us to be part of the unchanging order of things, because they surround us and we know them too intimately. The utopian dream - of freedom, of repose, of exuberant creation, of harmony, joy - tries to break through that. It insists that other things are possible, without spelling out in detail how. Blueprints of an entire alternative order rarely, in any case, escape elements of the ridiculous.

At the same time, a utopian vision that is entirely devoid of practical thinking, of at least the suggestion of alternative structures, procedures, ways of dealing with known problems or ones that can be anticipated, must surely be viewed today with caution. For without including any of this, such a vision contains a hole into which rather more unpleasant things can flow than freedom, harmony and the rest. Even Marx, for all that he was shy of blueprints, insisted on the necessity of finding links, emergent trends, within the present that might lead forward to a better future. And through not adequately thinking about the political realm of such a future, he bequeathed to the tradition that came down from him intellectual and practical deficiencies that were to become, in due course, catastrophic.

Therefore, yes, iconoclastic utopian thinking is indispensable - and it is insufficient.

(This is obliquely relevant; and so is this.)