My opinions and beliefs tend to sometimes be at odds......
The ba-ra-ka are the three distinct levels of the Soul....
As far as the Babylonians?? I think... it may have only come about during the times of the Egyptian Dynasties yet seeing as How the Egyptians took alot of thier cultural ideals directly from the Babylonians who in turn took thiers from the Sumerians I do believe it may be traced as far back as Sumeria....

First is the Ba.... which is the Vegetative state... akin to Trees.. which we have as those automatic functions of the mind... breathing... heart beat and such...
Second is Ra.... which is the Animalistic state..... these are our instincts and survival abilities....
Third is Ka.... this is the Reasoning State...... this is the part of our mind that actualizes our perceptions.... gives us the ability to communicate and describe experiences and form concrete conclusions.....
All three form the Soul or Spirit of Man and all that lives around him.....
I do believe we have a Soul... or Spirit... though what I believe of it would invariably incite debate I am sure....