What is a soul?

What is a soul?
A substance of its own
That flames a human life within?
Or, may be, it is just a moan,
A sole moan,
Piercing like a knife of steel
Your whole body
Miraculously bringing
The will for peace
And always dreaming
Of the tranquility 
Above the clouds of sins?

What is a soul?
Shall I leave unanswered
This sacred secret
In the dawn of time?

I simply close my eyes
And treasure something
Which like a little baby's
Crying deep inside.