The starting point of our Knowledge Cafe is the fact that monetary phenomena have significant impacts on the real economy. There is no such thing as "neutrality of money" (i.e., the notion that given the technology and preferences of agents, monetary phenomena do not affect the outcome of market processes). On the contrary, money matters in fundamental ways for modern capitalist economies, whether we look at them from the aggregate perspective (macroeconomics) or at a micro level. These monetary phenomena affect every agent in the economy, whether large corporations or small-scale subsistence farmers. And they help shape the resource management practices of these actors. Thus, monetary phenomena have critical implications for sustainability. One very important aspect here is the question of monetary creation and circulation in modern economies and how these affect inequality, both at the national and international levels. The question of fiat money and the different forms of social control will be at the center of our discussions. We will also discuss different ways of thinking about money. Modern economic theory sees in money an instrument, a transactions technology. Ancient thinkers saw money as an ethical and political object. These different perspectives will be considered in our analysis of how monetary justice related to long-term sustainability.