With the number of brain injury cases observed and the continued advances in neuroscience, this has proven to be strong evidence for materialism. By defining what Cartesian dualists and materialists mean by 'brain', 'mind', 'body' and 'soul', one will reach an argument for Cartesian dualists, which responds to the evidence for brain injury with the claim that the brain it is only 'an instrument of the soul'. This will lead to the conclusion that there is stronger contemporary support for materialism due to neuroscience and that the Cartesian dualism argument as it stands may be wrong. Yet future neuroscience discoveries may continue to argue that significant parts of both theories are wrong, meaning that materialism as it stands may not be correct either. The mind-body problem forms the basis of the philosophy of mind argument. Descartes, a rationalist philosopher and scientist, was the first to propose a coherent and thorough theory, known as Cartesian dualism, which assumes that “the mental and the physical – or mind and body or mind and brain… are radically different kinds of thing ” or in other words, humans have a “non-physical soul that exists independently of our body.” Descartes believed that the soul (or spirit) contained all of our mental states. In this way he used the words "soul" and "mind" as synonyms. The latter could create confusion with the idea of ​​materialism so, to avoid contradictions, the soul will be defined as “the non-physical aspect of a person” while the mind will be defined as “a set of your mental states”. While the brain will be defined "as the organ that controls mental states and the nervous system" in accordance with the definition of the body (that matter... in the middle of the paper... he even admits: "...neither dualism nor materialism can still explain all the phenomena that need to be explained.” Future neuroscience might perhaps find even more significant parts of both theories wrong. Works Cited Andrade, Gabriel, “Immortality,” Internet Encyclopedia of Philosophy, http://www.iep. utm.edu/immortalBeauregard, Mario – The Spiritual BrainCampbell, Keith – DualismsChurchland, Paul - Matter and ConsciousnessDescartes, Rene – Selections, from Meditations on First PhilosophyEccles, John Popper, Karl – The Self and its BrainRobertson, MD – Dualism versus Materialism Robinson, Howard, “Dualism”, The Standford Encylopedia of Philosophy, http://plato.standford.edu/archives/win2011/entries/dualismStolijar, Daniel “Physicalism” The Standford Encyclopedia of Philosophyhttp://plato.stanford.edu/archives/ fall2009/entries/physicalism