The novel of ideas was rejected by British-based modernist writers. In the international literary sphere there was less hostility to the fictional representation of philosophical, political and religious ideas, and there was also significant critical discussion of literature as a specific kind of speculative thinking. Outside Britain the representation of ideas and the formal experimentations of the modern novel were not seen as being in conflict with one another. Writers at the forefront of developments in the novel, including Fyodor Dostoevsky, André Gide, Thomas Mann, Rabindranath Tagore and Jean-Paul Sartre were both formally experimental and engaged with the novelistic implications of philosophical, religious or political thought. In this chapter I consider two kinds of modern novels of ideas, the ironic and the dialogistic. I focus on the writing of John Galsworthy in relation to Thomas Mann’s ironic Buddenbrooks and Graham Greene’s The Power and the Glory in relation to André Malraux’s dialogistic La Condition Humaine.