An outline of "Marxism" had definitely formed in the mind of Karl Marx by late 1844. Indeed, many features of the Marxist view of the world's political economy had been worked out in great detail, but Marx needed to write down all of the details of his economic world view to further clarify the new economic theory in his own mind. Accordingly, Marx wrote "The Economic and Philosophical Manuscripts". These manuscripts covered numerous topics, detailing Marx's concept of alienated labour. However, by the spring of 1845 his continued study of political economy, capital and capitalism had led Marx to the belief that the new political economic theory that he was espousing – scientific socialism – needed to be built on the base of a thoroughly developed materialistic view of the world.