well, if fear ultimately leads to death (via hatred and suffering), then the origins of fear is ultimately death. and if you think about it, you can see fear reaching backwards from your "death" towards you.
breaking the cycle psychologically, transcending, is bliss. language is a powerful portal into understanding this and experiencing it. we seem to forget that in retrospect. tolle, as said, is a master of language in a languageless land. and as also said, the mystical traditions of pretty much all h sapien branches are about coming into contact with this bliss in some convoluted way.
personally: fear is the ultimate joke because death is the ultimate joke. when that is stumbled upon, the rest is just laughter. because, ya, it's pretty funny sh!t. i mean, isn't the way past fear also radical acceptance of it? and to accept it, you have to know its roots.
after ego death, physiological death seems like an odd requirement.
tetra