Theories of global justice are often criticised for being ineffective or unrealisable. The aim of this interdisciplinary thesis is to examine whether this motivational criticism holds regarding Singer’s Principle and Pogge’s theory of global egalitarian justice. First, I will show that the effectiveness argument is unconvincing: the underlying effectiveness criterion is either incoherent or not defined, and existing effectiveness predictions are empirically unsatisfactory. Second, I will analyse whether Singer’s interactional Principle satisfies the ‘ought implies can’ (OIC) criterion, which holds that obligations must be within the capacities of individuals. Having discussed the rationale and standard of the OIC criterion, I will show that the philosophical literature does not offer a convincing empirical justification of possibility evaluations. Drawing on psychological explanations of moral heroism, I will conclude that compliance with Singer’s Principle is possible for ordinary persons, i.e. that ‘every person is a hero in waiting’. Third, turning to the feasibility of Pogge’s theory of global egalitarian justice, I will discuss how the standard, time-frame, weight and rationale of the feasibility criterion should be defined. Based on psychological and sociological explanations about moral behaviour, social norms and identity, I will evaluate the empirical arguments advanced in the philosophical literature. In addition, I will consider how the long-term trends of globalisation are likely to influence the role of nationality, identity and global institutions. I will conclude that Pogge’s theory of egalitarian global justice is conditionally feasible, i.e. if we assume that domestic egalitarian justice is feasible. This implies that nationalism will not necessarily play a dominant role during the centuries to come. Overall, possibility and feasibility evaluations remain uncertain and partly subjective. I will thus argue that a burden of proof should be established to limit the negative effects of false evaluations.

This paper criticises the famous “”ought” implies “can”” on the grounds that its main claim - that there can be no unfulfillable obligations - is false. The first part of the paper investigates the use, history and previous literature on the topic, as well as the proper understanding of the principle. The second part presents the main argument, directed at the interpretation of “”ought” implies “can”” as a conceptual truth. It is argued that it must be possible to split the meaning of the term “ought” into component parts, parts that must each be quite capable of functioning on their own. The result is that we cannot conclude that one part of the term “ought” (such as whatever is its moral content) must disappear just because another part of it (such as “can”) does so. Finally, in the third part, we tackle some common arguments and intuitions in favour of the principle, and provides a few concluding words and a summary. / Den här uppsatsen kritiserar den berömda “”bör” implicerar “kan””-principen, (här tolkad som “konceptuell implikation), på så vis att principens viktigaste punkt är falsk, nämligen idén att det inte kan finnas några ouppnåbara plikter. Uppsatsens första del undersöker användningen, historien och litteraturen bakom ämnet, samt formuleringen av principen. Den andra delen presenterar huvudargumentet, riktat mot ””bör” implicerar ”kan”” som en konceptuell sanning. Argumentet fungerar på så vis att det måste vara möjligt att dela upp meningen i termen ”borde/bör” i komponenter, komponenter som måste vara kapabla att fungera även på egen hand. Resultatet blir att vi inte kan dra slutsatsen att en del av termen måste försvinna (såsom dess moraliska innehåll) bara för att en annan del av termen (såsom ”kan”) gör det. Slutligen, i den tredje delen, så behandlar vi några vanliga argument och intuition som förs fram till principens försvar, och summerar texten.

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal.

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal