This paper contends that carving out pathways to finance the sustainable development goal (SDG) agenda entails to reconsider tacit assumptions regarding the functioning of financial systems. We first use a history of economic thought perspective to demonstrate the flaws of the loanable fund theory, which has come to underlie SDG finance strategies. We then introduce the alternative endogenous money theory using a consistent theoretical and accounting framework. This allows us to identify and discuss a set of financing mechanisms that would permit to bridge the SDG budget gap. These mechanisms include the issuing of sovereign green bonds, the modification of the European Central Bank's collateral framework, changes in capital adequacy ratios, a market of SDG lending certificates and the introduction of rediscounting policies. We back up the discussion with examples from economic history.Sustainability 2020, 12, 2775 2 of 22 that market prices signal the true value of financial assets, and that social welfare results from the maximization of investor wealth) need to be re-examined [12].It is within this broader context that this paper seeks to make three specific contributions to the literature on SDG finance. First, we contend that bridging the SDG finance gap requires excavating-and critically assessing-a set of tacit beliefs, which seemingly underlie the current framing of finance research and policies. Social studies of finance have indeed established that the behavior of actors (and the legal/technical system within which they operate) is shaped by underlying theoretical representations [12][13][14]. As stated in Chambost et al. (2019, p.3): "financial theories are embodied in tools, rules and artefacts acting as vectors influencing and legitimizing financial practices". We hope to fill a gap in this literature by showing that one specific conception of money and finance-the loanable fund theory (LFT)-has fundamentally influenced economic policy over the course of the past four decades.Second, we use a history of economic thought perspective-going back to the original texts-to show that the LFT does not properly account for the mechanisms of credit creation, and provides, overall, an inaccurate portrayal of the relationship between finance, savings, interest rates and investment in the real world. Several major economists (Schumpeter, Wicksell, Keynes) and central bankers around the world, have repeatedly demonstrated the logical flaws of the loanable fund theory [15]. This leads us to highlight that the LFT is a powerful-yet concealed-mental hindrance to the development of appropriate SDG finance policies.Third, we offer an in-depth discussion of the alternative endogenous money theory championed by post-Keynesian authors. We use a sound accounting and theoretical framework to carve out policy pathways for "mission-oriented" public and private investment in response to SDGs. In so doing, we contribute to recent research in ecological post-Keynesian macroeconomics [16] and to the discussion of policy proposals...