Man himself is sole cause of his own misery.

Get rid, then, said the Buddha, of these passions, these strivings for the sake of self, that hold the true soul a prisoner.

They have to do with things which we know are transitory: how can they be immortal themselves?
We recognize them as subject to our will; they are, then, not the I.
As a man, he taught, becomes conscious that he himself is something distinct from his body, so, if he reflect and ponder, he will come to see that in like manner his appetites, ambitions, hopes, are really extrinsic to the spirit proper.

Neither heart nor head is truly the man, for he is conscious of something that stands behind both.

Behind desire, behind even the will, lies the soul, the same for all men, one with the soul of the universe.