What is materialism in metaphysics?
Answer by Tony Boese
Materialism is, in a very simplified form, a position arguing that all things are reducible to material components. My exposure to materialism is almost exclusively through the Philosophy of Mind, but I do find the Mind perspective the easiest to get one’s mind around (no pun intended) anyway. So, consider consciousness. The debate is between those that say consciousness is something beyond the basic substance and processes of the brain and those that say that consciousness is nothing more than (a) part and participle of brain processes or (b) (a weaker claim) that it is nothing more than a byproduct of the physical process. Granted both of these camps have numerous iterations, but this is a simplistic characterization.
One thought experiment that will illustrate the idea well (though perhaps not convince you one way or the other) is Mary the Super-Scientist (http://en.wikipedia.org/wiki/Mary’s_room).
Beyond Mary, the general materialist position follows a similar if broader path aiming at showing there is nothing that is not material and the direct byproducts of material things. First it takes for granted such premises as (1) the conservation of matter, (2) that the universe is made of nothing but matter and void (if not only matter), and (3) the universe is finite in space and time. Then the argument advances, adding in (4) the mind cannot produce something with independent existence, and therefore concludes (5) matter is all that exists, and so there can be nothing non-material that can also be said to exist.
So, consider something like consciousness. The idea would therefore be that since consciousness only exists in/due to the mind, and the mind cannot be generating material things, yet it does seem to clearly be generating consciousness, then this consciousness must be nothing more than part of the processes, or at least a direct byproduct of the processes, of the mind.
Why do we think and feel that the physical and the spiritual cannot be reconciled?
Answer by Jürgen Lawrenz
We humans have, on the whole, a heavily binary orientation on life and the world. Something is either dead or alive, black or white, here or not here, straight or crooked, yes or no, true or false. You can extend the list at your pleasure.
But you need only look at ‘true or false’ to see at once that it doesn’t work this way in some very important situations. Except in cases where the answer is clear cut (someone told a lie), the ‘truth’ has many colours and means different things to different people, in different cultures and religions, and so on.
Binary thinking has its virtues, of course. But the issue you have asked about is the one where it falls down absolutely.
Nearly 400 years ago, Descartes gave us a (binary!) definition: Physical things are res extensa – they are spatial, therefore they can be weighed and measured. Non-physical things are res cogitans, ‘thinking’ things. That definition gave (a) a clear cut notion of an object on which we can do research or use it some way for our benefit and (b) a clear cut idea of human souls or minds, angels, gods etc.
But res cogitans are not extended, they are not things. And so an answer to your question is possible in binary terms, and only in binary terms: spiritual things have no surfaces, corners, hooks etc. by which they can touch material things. Nor can they make themselves heard by vibrating, or seen by generating colours and shapes.
Millions of people continue to believe in spirits and spiritual states of mind. Now there is no possible binary reply to that! The only possible reply is: impossible!
Yet there is a hitch in this. If you asked the same people who cry impossible, ‘are you alive?’ they would reply ‘yes, of course!’ But life is not physical! So where does this leave them?
In short: it is a problem that rests on the manner in which we experience life. Sensory experience is immediate and deals with clearly existing things, facts and events. But when we look for explanations on things, facts and events that we cannot directly experience, we leave the physical world to itself and begin speculating on non-material aspects of existence. Science cannot deal with them, and so we have two options: to deny that they exist or else that everything spiritual can ‘ultimately’ be reduced to physical states.
But this is a matter of whether you choose to believe it.
You have the choice of believing in spiritual states and no scientist has the power to prove that you are mistaken. Conversely you may be a scientist who still believes in spirits or spiritual states. But you cannot prove they exist.
And that’s the essence of the predicament. We humans have a pronounced hankering for spiritual life, and we often downgrade the physical world because we think the former is ‘higher’. I think this is as bad a mistake as denying it. Humans have the capacity for both kinds of existence. Just being alive is the strongest possible argument. But again, that’s not something I can prove to you or anyone else. (I’m working on it!)