Mind–body dualism
Ontological dualism makes dual commitments about the nature of existence as it relates to mind and matter, and can be divided into three different types:Substance dualism is a type of dualism most famously defended by René Descartes, which states that there are two kinds of foundation: mental and body. This philosophy states that the mental can exist outside of the body, and the body cannot think. Substance dualism is important historically for having given rise to much thought regarding the famous mind–body problem. Substance dualism is a philosophical position compatible with most theologies which claim that immortal souls occupy an independent realm of existence distinct from that of the physical world.
Dual economy
Dual economies are common in less developed countries, where one sector is geared to local needs and another to the global export market. Dual economies may exist within the same sector, for example a modern plantation or other commercial agricultural entity operating in the midst of traditional cropping systems. Sir Arthur Lewis used the concept of a dualistic economy as the basis of his labour supply theory of rural-urban migration. Lewis distinguished between a rural low-income subsistence sector with surplus population, and an expanding urban capitalist sector (see Dual-sector model). The urban economy absorbed labour from rural areas (holding down urban wages) until the rural surplus was exhausted.