This study is a critical exploration of the ethical implications raised by the notion of "tolerance" as presented by the American Philosopher Thomas Scanlon in the context of his moral philosophy according to contractualist theory. The paper thus explains the difference between Contractualism and the three principal theories of morality in Western culture: Utilitarianism, Kantian ethics, and Virtue ethics. It then defines the moral foundations of human conduct on our which Scanlon's Contractualism is based and how it dictates our perception of the motives behind our moral behaviour and the way we can reasonably justify and deliberate in the realm of morality. The paper then analyses the concept of "tolerance" and its paradoxes, before concluding with a critical assessment of Scanlon's Contractualism and the way he approaches tolerance within this methodology.