The mere fact that he came there. That's what I've always thought. Rights are not granted: they are taken. You have the right - especially when the higher things are concerned - simply because you dare. The Tower is there for anyone who can get to it - and what is inside confirms me in that opinion. Moreover, I think the Tower is there because someone constantly walks towards it, and takes - by force - his right of entering. The whole existence is there because someone is risking his own soul (not only life); saving his soul is the antithesis, they are contradictory but ultimately one is impossible without the other.
Maiorem hac dilectionem nemo habet ut animam suam quis ponat pro amicis suis.