Was the Keynesian message alive during the second half of the XXth Century, or was it betrayed by his followers? This article in the fields of the history of economic thought and methodology contrasts the Scientific Research Programmes (SRPs), a Lakatosian concept, of Keynes in The General Theory of Employment, Interest and Money (TGT) with those of its immediate orthodox schools: Monetarism (MS), Neoclassical Synthesis (NS), New Classical Macroeconomics – rational expectations – (RE) and General Disequilibrium (GD). The objective is to to assess the immediate impact of Keynes's vision in economics. It can be concluded according to this comparison that Keynes's bequeath was alive during the period between 1950 and 1980, but that it was accepted under different names. Many economists deny this statement. However it is hereby argued with the help of Lakatosian methodology that in both economic and philosophical terms the MS, NS, RE and GD SRPs are degenerative variants of Keynes's SRP. The Keynesian reasoning chain – a non self-regulated system, non neutrality on the part of money, organicism, non-ergodicity, historical time and uncertainty – is misunderstood and hence misapplied on the part of these deviant schools, or transformed into “bastard Keynesianism”, to quote Joan Robinson (Joan Robinson, 1975[1973], 125). In other words, Keynes's economics is different from Keynesian economics as was firstly proposed by Axel Leijonhuvfud (Leijonhuvfud, 1968). The internal history of macroeconomics in those periods is undertaken, since it is is the rational reconstruction of the meaning of a SRP.Section 1 is an introduction to basic concepts related to philosophy of science and methodology, especially Lakatosian methodology, which can be skipped by the specialized reader. Section 2 is an analysis of Keynes's hard core in his SRP, also being an introduction to the problem as it outlines Keynes's thinking, Section 3 describes initial Post Keynesianism, which was faithful to the original message. Sections 4, 5, 6 and 7 outline the hard cores of Monetarists, Neoclassical Synthesis, New Classical Macroeconomics and General Disequilibrium, respectively. Section 8 is a comprehensive analysis of the differences between the mentioned paradigms, and hence concludes. References are listed at the end of the article