What is the difference between man's soul and spirit? It is easy to recognize the body as the physical matter that makes up a person.  The body is clearly distinct from the soul and spirit in several ways:


The body is visible to others.  (When I see you, I am seeing your body.)
The body is recognizable by others.  (I know who you are when I look at you.)
The body has a beginning and an end.  (Our bodies experience conception/birth and death/decay.)
The body directly interacts with the rest of creation.  (We touch, eat, move things around, etc.)


Are there similar comparisons that help describe the distinction between the soul and spirit?  I'm specifically interested in the viewpoints of those who believe in the tripartite nature of man, that is, that the body, soul, and spirit are the three distinct components of a person.
There is an interesting passage in the magnificat in Luke,

The phrase in verses 2:56,47   seems to indicate that Spirit and Soul basicly mean the same thing. Jewish verse uses a technique called parallelism where one line says something, and the next ,the same thing but using diifferent words for emphasis. 

It might be pushing it a bit but the phrasing here does tend to present an interterminology and holistic viewpoint of the inner aspect of man. 

Logicaly to say that there are two seperate parts of Mary rejoicing or exulting leads to an assumption that there are two independendant self consciouse, self expressing entities with in one person, who by the way is aware that they are present and active! Such a conclusion does not make sense.Especialy to the Jewish thinking, which was not so clear cut as the Greek dualism of the time. Up to that time many scholars indicate that the view was held that the body and the soul were a composite whole one linked to the other and not seperate in the way that later Theology developed and expressed the nature of man. 

Therefore we must conclude that these terms "spirit" and "soul" refer to the immaterial part of human beings and are aspects and interchangable terms of expression of these.

I feel it is rather difficult and confusing to try to define too clearly the various parts of the above in terms of differentials. Especialy with those are all used in the NT particularly.

There are mysteries within the acts of God that are beyond our comprehension.cf Psalm 139. The problem we have is that we always want things to be 2+2= 4. It is just not that easy to come down hard and fast and defend a particular emphasis on the Biblical expressions of the nature of mankind.

In the classic text in Thessalonians Paul seems to be making a tri-partite affirmation, but it could well be he is using interchangeable terms to relate that he is talking about the entirety of the human being. Once again a kind of parallelism or overstatment for emphasis to give fullness of meaning could be the style in this passage. The rich vocabulary of the Greek Paul used gave ample opportunity for this kind of prose.

In summary the full data of the scripture uses the terms spirit, soul, and even heart interchangeably and the context indicates the process or functionality rather than a difference in substance or place within a human being. To press one or the other to make an absolute point of reference and fixed meaning tends to move away from the holistic view that the biblical record suggests.