In Kabbalistic terms the “Soul” consists of many aspects, the three main aspects beings the Nefesh or Instinctual/Lower Self, the Ru’ach or Awake/Middle Self and the Neshamah or Divine/Higher Self. The Nefesh is that which is intimately enmeshed with the physical body and during the period the fetus is in the womb, the Ru’ach enters the body. Ru’ach is therefore the consciousness, the You, the aspect that lives in the NOW, and so does not retain memory, but is rational, whereas the Nefesh retains all memory and has access to all knowledge, but is not rational in the same terms.
Although there is no direct connection between the Ru’ach and the Nefesh, you as the Ru’ach can gain control over the Nefesh by befriending it, after all it is the part of you that really should become your own best friend. By becoming friends with your Nefesh, which in many respects can be viewed as a separate part of yourself (but bear in mind still part of the You), you can gain control over memory (and there is a huge storehouse to go through) and how you as a person interact with every day life through the five senses. This very important relationship can also lead to healing of your physical self:
“It is said that you, the “Awake Self” or Ru’ach, have no direct part in the Nefesh, no direct connection with it, yet you are able to control it if you manage to establish a good relationship with it. If not, its control over you could result in all sorts of psychological problems like schizophrenia, manic depressiveness, or what is now termed “bi-polar disorders.” It has been indicated that the majority of humans over the age of three years, have a poor relationship with their “Instinctual Selves.” This appears to be true when you study people, and discover that very few of them are friendly with, or even like, their own “Vital Selves.” “
~excerpt from The Book of Creation by Jacobus Swart
Now, for many years I have formulated my own impression and ideology of how parts of the Being interact with each other during life and what happens to them upon death. My ideology goes something like this. There are three main parts, the Body, Ego and Soul. The Body is created, the Soul enters the Body and the Ego glues the two together during life. Upon death, the Body breaks down, the Soul moves on and the Ego remains behind for some time as an energetic parcel. There is a bit of a discussion on this in my own book, The Reality of Things:
“The Phantasm I speak of is often seen as the “ghost”. The “Body” of a person can be broken down into three essential parts, the Shell (physical body), the Ego, and the Soul. It is the Ego that acts as the glue and keeps the Shell and Soul together. Upon death the Shell ceases to operate and the energy that makes up the physical body starts to disperse. The Soul moves on over the Bridge and the Ego is left as an energetic form. It is this energetic form of the person which contains the person’s memories and the physical appearance that people usually see or experience as a ghost. If you were to hold a coin in your hand for a while it would take on the temperature of your body. When you release the coin onto a cold surface the temperature of the coin does not change immediately, it takes time to become cold and attune to the temperature of the cold surface. The energy of the heat it contained is released slowly. The same happens here. When the body dies, the Ego moves out as an energetic form and over time it will disintegrate. However, in some cases, the intent of people, and the more people the better, can keep the energetic form fed, very much like the Servitor or Egregore. Therefore, the form of the person that was, remains in this existence for as long as people think of that person and interact with them, but remember that it is only a signature of the person that was.”
If we then relate all of this back to the Kabbalistic outlook, then the Ru’ach is the Soul, the Nefesh the Ego, and the Body is of course still the Body. The Ru’ach/Soul is the aspect that is in the NOW, and the Nefesh/Ego experiences through the five senses. Therefore, when the body dies, the Nefesh continues for some time, and can be kept alive by people who feed it more and more energy. The Nefesh holds all the memory of the person, the ego of the person, and so a “ghost” will retain all of the aspects of the person as they were in life.