Whereas there has been considerable debate about the social context of Darwin's theory of natural selection, much less focus has been placed upon Alfred Russel Wallace. This article looks at Wallace's socialism and, in particular, the influence upon his thought of the early nineteenth-century socialist Robert Owen. It argues that a case can be made for seeing Wallace's thought about nature and natural selection in the years up to 1858 in the context of Owenism. Three aspects of his thought are singled out for examination. These are, first, Wallace's views on the role of instinct in animal and human behaviour; second, the idea of colonization in human society and in nature; and third, a re-examination of the role of Malthus in Wallace's thought, emphasizing the influence upon him of the early nineteenth-century socialist critique of Malthusianism.