Substance dualism

• Substance Dualism: The belief that the mind and body both exist as 2 distinct and separate realities.
• substance dualism

  • the view that mind & body are separate substances which both exist.
• Substance

  a subject which has various properties
• Is the mind a substance which has properties or is it something else?
• Substance dualism

  • substance of human = body.
  • body - subject that has many properties (substance)
  • body has property of 'extension' - takes up space & has measurements.
  • mind is not physical & not extended but does have properties of thought.
  • 2 are attached to each other & form human being.
• Pythagoras, Socrates & Plato

  • We have an essential non - physical self which could be capable of existing without body.
• 'I think therefore I am' - Descartes
• Hyperbolic doubt (D)

  • Think about all things he thought could be known & rejected them if there was any doubt at all of their certain truth.
  • He was able to establish beliefs have both endurance & stability.
• Descartes rejected the idea that sense perception can give us certain knowledge of the world because our senses can easily be misled.
• 'first certainity'

  • The fact that he was thinking sceptically.
  • He couldn't doubt his own existence as a thinker, because he would have to exist as a thinker in order to be able to do doubting.
  • 'I think therefore I am'
  • Later revised to 'I am, I exist'
  • Descartes was sure he had a mind (he was thinking & doubting) but wasn't certain that he had a body.
  • Therefore, mind & body had to be 2 distinct things.
  • mind has something peculiar that we cannot doubt its existence; whereas existence of body can be cast into doubt.
• Body has different parts (hand, ears) whereas mind couldn't be divided into parts. (D)
• Property Dualism

  • there is only one kind of material, physical substance but 2 distinct kind of properties: mental & physical properties.
  • physical matter of brain has physical properties but also has mental properties (opinions, emotions).
  • Emergent materialism - idea that physical things become more & more complex, new properties emerge from them.
  • Mind has own existence in some sense but not completely separate substance from physical. - held by Mill
• Reductive materialism

  • theory of mind which has lots of different names, including 'identity theory' & 'type physicalism'.
  • Mind is not distinct from physical brain but is identical with it.
  • Mental states are 2 different types
  • memory, pain & happiness correspond to activities in different parts of brain.
  • Chemical reactions - we feel emotions or make decisions that correspond to that part of brain
• Reductive materialism & LAD

  • No room for concepts of life after death.
  • no way in which the 'self' or consciousness could leave behind physical body at point of death because consciousness is physical & is nothing more than physical - when body dies, consciousness ends.
• Descartes thought that the pineal gland was the 'seat of the soul'
• Epiphenominism

  • Beer - bubble at the top is soul and physical is the liquid/ chemical interactions in body.
  • Soul is a by product of chemical/material interactions.
  • mental aspect is caused by physical interactions.
  • soul cannot affect material interactions, it is created by it.
• Mind & body must be separate substances

  • they can be treated differently, mind is immaterial & thinking whereas body is physical. Body can be divided into parts which can be removed but mind is a singular whole.
  • Mind/consciousness is part of me that holds essence of personhood. Eg. someone given a face or body transplant is same person because their mind is same.
  • Descartes gives explanation of how body & mind interact through singular pineal gland. - solves problem of how an immaterial mind communicates with material body.
• Mind & body cannot be separate substances

  • Against Descartes - if someone's body is altered (leg amputated), their outlook on life, personality & mind may be altered as well. - suggest the mind & body are more closely connected than Descartes allows.
  • What makes a person? - a person may be recognisable by how they look or by their mannerism & how they speak.
  • Medical research found function of pineal gland. Pineal gland secretes hormones & help regulate sleep = unlikely to be point of contact between mind & body.
  • How can immaterial mind communicate with material - like a 'ghost in the machine' - how can a ghostly phenomenon pull levers to make machine work?
• Daniel Dennet

  • substance dualism describes mind as Cartesian theatre.
  • idea that mind is like a theatre where I am audience of one.
  • It would be like watching a screen or play except I am only member of audience.
  • 'I' am inside my head, looking out, watching & controlling all my actions.
  • Dennet argues this is an incorrect understanding of mind because mind doesn't work like this.
• Pineal gland

  • there are 2 of everything else in body but only one of pineal gland.
  • pineal gland was home of singular thought as well as where imagination & common sense are found.
• Ryle

  • traditional mind & body distinction was a 'categorical error' because it tries to treat mind & body as if they are 2 different things of similar logic when they are not of the same category.
• Ryle - team spirit

  • Just as team spirit is not found in addition to the team but is a way of describing how the team works, the 'soul' or 'mind' is not an addition to the physical person but a way of describing a person's functions.
• It is category error to talk of body & mind as separate substances

  • Personhood involves every aspect of physical & mental. Thinking part of 'me' is not something that can be categorised & separated. Its like a ghost (non-material) trying to work a machine (physical) - it couldn't work.
  • Use of language is inaccurate; it is category error because body & mind cannot be described in same way. (team spirit)
  • Body & mind are not distinct (separate) because both describes what it means to be a person. Ryle argues it is like saying I have a left glove & right glove but not a pair of gloves - both phrases describe same thing.
• Not category error to talk of mind & body as separate

  • the miind directs actions of body, so body & mind as separate substances helps to understand personhood & what makes me 'me'.
  • physical body & mind are different type of substances - one is physical & other spiritual/immaterial - Descartes - body can be divided & physical sensations & movements are different from mental processes.
  • Descartes - He doubted everything but was still thinking. I think therefore I am.