Quote:"The mutilation of the savage has it's tragic survival in the self-denial that mars our lives."
I'll give you some context:
"I believe that if one man were to live out his life fully and and completely, were to give form to every feeling, expression to every thought, reality to every dream - I believe that the world would gain such a fresh impulse of joy that we would forget all the maladies of mediaevalism, and return to the Hellenic ideal - to something finer, richer, than the Hellenic ideal, it may be. But the bravest man amongst us is afraid of himself. The mutilation of the savage has it's tragic survival in the self-denial that mars our lives. We are punished for our refusals. Every impulse that we strive to strangle broods in the mins, and poisons us."
As has already been mentioned, the 'mutilation of the savage' hints at practices which were considered to be that of savages (these days, everyone's got piercings

). Wilde believes these practices to be injuring man, and at a physiological level, he compares it to how humans - civilised, moderns ones - still cling to this severing of the self in the form of self-denial. E.g. we do not pursue the ultimate pleasures that we so desire, because of those indefinable things such as 'morals' or 'religion' or society's expectations, and what has been ingrained in us. In effect, we restrain our impulses, and by deliberating and checking ourselves instead of behaving spontaneously (read hedonistically), we are in effect denying our soul and thus making our lives miserable.
Once we overlook the 'maladies of medievalism' and become freer, we are closer to the Hellenic idea that Wilde is supporting here. It's been a while since I read Wilde, I'm assuming Henry Wotton says this while instructing poor Dorian...?
This reminds me of a quote I've read somewhere, which went like in denying part of the soul, you lose the whole, or something to that effect. The original sounded better