Abstract
We investigate the genesis of metaphysical physicalism and its influence on the development of Place's, Smart's, and Armstrong's ideas on the relation between the mental and the physical. We first reconstruct the considerations that led Armstrong and Smart to a 'scientific' world view. We call 'metaphysical physicalism' the comprehensive theory on reality, truth, and meaning which ensued from this world view. Against the background of this metaphysical physicalism we study Armstrong's and Smart's analyses of secondary properties and the genesis of their identity theories of mind and matter. We argue that fundamental revisions in Smart's theories on colour and consciousness were driven by his aspiration to fully work out the philosophical consequences of metaphysical physicalism. Finally, we briefly consider the role metaphysical physicalism has played in twentieth-century philosophy of mind.