Sustainable development faces numerous challenges when applied in the real-world global economic model of capitalism. The prevailing trend of the economic pillar, in the implementation of sustainability planning based on the triple bottom line (TBL), compromises both the environment and society. This paper aims to address such challenges by proposing a new vision of strong sustainability that is characterised by: i) considering the global economic model in a real-world approach; and ii) having strong core values of sustainability. To evaluate the first characteristic, a review of the literature regarding capitalism and TBL-sustainability has been conducted. For the second characteristic, a historical-philosophical discussion around the role of society and the economy has been conducted. The results suggest that an actual sustainable society requires a fixed and sustained focus on environmental and social pillars together with a flexible organisation of society (including its economic model).