Kant's great achievement was to recognize that the problem of dualism arose from the exaggeration implicit in the accepted conceptions of mind and world. Mind, having been defined as other than the natural world, could not then have its contact with the world explained. For Kant the mind constitutes reality; the world is an attainment of mind. Kant was succeeded by thinkers who extended and elaborated the mind's role in the construction of reality. In their work the mind was not just the medium in which the external world appeared it was the substance of experience itself. In short, human experience was identified as a dynamic network or system of judgements, as a "phenomenology'. In such a system the faculties and capacities of the mind are not innate or natural but are made to be; they are an historical achievement. The intellect is a product of culture; it is, itself, an artefact of civilization.