TEACH YOURSELF PHILOSOPHY OF MIND, Mel Thompson, Teach Yourself Books, London, 2003 seems to offer evidence that immaterial or non-material souls do exist.  Or does it?  Let us take a look.

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Consider Plato’s thought in Timaeus that the psyche is self-moving. Plato saw the psyche as the power to move things without being controlled by the physical. When the psyche goes away from the body only a corpse is left (page 7). Plato then thought that the soul pre-dated the body. It was like it went into the body and controlled it and when it left the body was just an object, a dead thing.
 
REPLY: Things move without being moved by anything conscious. The psyche could have hidden physical forces that make it move. To say that the consciousness gives life to the body and that something goes away from the body when it dies is as silly as saying that something goes away from a clockwork toy when it stops moving around.
 
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A surgeon replaces your entire body with new parts. You will still be the same person. The soul is the form. It makes you, you. The form is something that doesn’t depend on what parts you have got. Form is what makes you what you are. It defines your essence (page 13).
 
REPLY: This might only work if the surgeon doesn’t do it all at the one time. But consider this. There is John and there is Simon. If a surgeon puts Simon’s leg on John and soon John is entirely replaced by Simon’s parts, the result will not be John but Simon. All you will have done is taken Simon apart and reassembled him in the operating theatre where John was.
 
The argument violates our commonsense feeling that X's body is X.
 
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Most philosophers believe that mind and body are real and that dualism is true but how the mind works the body is a matter of debate (page 20). However it is possible to be a dualist without holding that mind and body are totally separate (page 43).
 
REPLY: There is a link between mind and matter in the sense that if your brain is damaged you can become like a different person. This makes it possible that mental states are ultimately physical forces caused by the brain. We cannot explain matter for there is so much we cannot understand. So why should the mind and exactly what it is be clear to us?
 
When we don't really know what the mind is or how it is, we cannot endorse any form of dualism.
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You can close your eyes and try to imagine that consciousness doesn’t exist but you will fail. This is because thinking or consciousness is an experienced process. The problems for mind body philosophies are the questions of,

Does this process have a physical origin?

Is it a substance?

How does it relate to the world of matter?

Can it do anything? (page 31).
 
REPLY: The last point is concerned with the fact that consciousness in itself does nothing at all. It is like the idea that you have a body equipped with the faculties of reasoning and free will and the consciousness needs them to do stuff. By itself it can do nothing. The body impulses force the consciousness to look at the television for example. It does nothing but is just controlled by the faculties and impulses of the body it is tied up with.
 
None of the questions can be answered conclusively by saying that the consciousness is some kind of non-physical thing.
 
The fact that an eye can see does not prove to the eye that sight exists. There could be an eye that can’t see anything for there is nothing but darkness but which would be able to see things if it had light. This eye will not know that sight exists. So the eye will not know what it is. It will not know if it is spirit or matter. The argument that the consciousness is separate from the body because it is like an eye that can see itself and so is supernatural is wrong.
 
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Consciousness or awareness is what responds to information and processes it (page 80). If this is so, then everything has some level of awareness. The thermometer for example is aware of temperature (page 81). For something to have a mind it must have the power to intend.
 
REPLY:  But consciousness by itself may simply be aware. The consciousness is aware of the memory and understanding and the will processing things. But it does not do the processing itself. It is those faculties, the memory and understanding and the will that we are conscious of that do the processing not the consciousness itself. For example, with brain damage a person may not be able to reason anymore but they are still conscious. Their consciousness is intact.

It has only lost some resources outside of itself.

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Plato taught that all true knowledge was a matter of memory or remembering (page 84). Plato held that there are things in the mind that we know and ideas that we have before we experience them and based an argument for reincarnation on that (page 84). It has been argued against Plato that if ideas are implanted in me, then how do I know they are real?
 
REPLY:  The ideas could be implanted without reincarnation. If I see a pink ball that does not prove that there is a pink ball there. Insane people think God is their poached egg with equal conviction. 
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Sartre argued that consciousness is always consciousness of something so it is not an entity in itself (page 146). Consciousness is total emptiness in the sense that it senses all things but itself. Once you try to become aware of your own consciousness, you are trying to see it as a thing and it isn’t a thing. You are trying to make an entity, an object and a thing out of what is subjectivity or non-thing which is impossible. Consciousness is the same as an eye that can see everything but itself.  
 
REPLY: If you cut off all the senses, consciousness would be aware of nothing except that it is aware. Consciousness is awareness and sensation. It is a sense that the five senses feed data to. It does sense itself.
 
The argument is getting at the notion, "Consciousness is not an entity, therefore it is a soul." If consciousness is not an entity then it is nothing. The argument implies that the faculty of consciousness cannot be there unless it is conscious of something. That is nonsense. It is like saying there is no eye unless it can see.