Synopsis: Radical alternatives, in terms of ideas about science in society, about economics, ideology and institutional arrangements should be included among possibilities considered within the scope of a pluralistic philosophy. While all these aspects of our mental maps are interrelated and important, economics plays a key role in attempts to get closer to a sustainable society. Mainstream neoclassical economics is not enough. The tendency to exclusively rely on this particular theory is considered part of the problems faced. A 'sustainability economics' more in line with dominant ideas of democracy is proposed, emphasizing the ethical, ideological and political elements. Reference is made to institutional theory but the principles and concepts suggested are in many ways similar to other kinds of heterodox economics and developments in other social sciences. Neoclassical economics is used as a point of reference in pointing to alternative ideas about human beings, organizations, markets, decision-making, efficiency, rationality, progress in society and institutional change processes. Predilection for such an alternative conceptual framework (or for neoclassical economics) is not exclusively a scientific choice but as much a matter of political and ideological preferences. One paradigm may be dominant at a time, but because of the ideological specificity of each paradigm, competing theoretical perspectives should be accepted and even encouraged in a democratic society.