It is a central prediction from mainstream evolutionary biology that there is a continuous set of intermediate states in the mental abilities from an ape-human ancestor to modern humans. A quick analysis is given to the problem introduced by Rene Descartes of the supposed gap between mind matter and physical matter, the former distinguishing humans from all other animals. A three-pronged analysis is then given that revolves around: (1) the continuity of mind from young children to adults; (2) the similarity of measured mental abilities between young great apes and young children at similar stages of development; and (3) the observation that there appear to be no unique genes in the human genome for mental abilities (including for ‘wisdom and intelligence’). The components that are required for language are then analysed, and important precursors found in the great apes. The conclusion is that the best supported hypothesis, especially in a Bayesian framework, is for a continuum in mental states between an ancestral ape and modern humans. There are a range of predictions from this model that can, and have been, tested.