Buddhism does not propose man does not posses a soul.
Anatman expresses the Buddhist understanding that we do not have a permanent, unchanging, self. Our self is like the flame of a candle. As the candle burns out, another is lit from it. The flame of the new candle is a continuation of the old one. It is the same, and it is not the same. I talk more about it in my write-up on nirvana.