With the early success of the deep ecology movement in attracting adherents and with the increasing threat of a global ecological catastrophe, one would have expected this movement to have triumphed. We should be in the process of radically transforming society to create a harmonious relationship between humans and the rest of nature. Instead, deep ecology has been marginalized. What has triumphed instead is an alliance of managerialism, transnational corporations and neo-liberalism committed to replacing communities with markets and transforming every facet of nature and society into means for increasing profitability and GDP. This outcome is explained here by the failure of deep ecologists to understand the ideological, political and economic forces driving ecological destruction, and thereby what is required to overcome these. To regain the initiative, it is argued, it will be necessary to recover the whole project of the Radical Enlightenment upholding the Renaissance quest for liberty that was subverted by the scientific materialism and possessive individualism of the Moderate Enlightenment. Not only will it be necessary to transform science to develop a comprehensive alternative conception of nature and humanity and its destiny, it will be necessary to revive and develop the institutions of the Radical Enlightenment to subordinate markets to democratically organized communities at multiple levels, as communities of communities committed to augmenting the life of these communities, including the life of ecological communities. Doing so will involve reformulating the grand narrative of emancipation as a dialogic, polyphonic grand narrative to orient individuals, organizations and nations to create a global ecological civilization.