Blind Desire:

[Ribo]

"Although gold dust is precious, when it gets in your eyes, it obstructs your vision." ~Hsi-Tang

Blind Desire

The strength of a man is to found in his heart, -- grammar is poor and doesn't seem intentional - "to be found" would be ok. Better yet swap this around to be something like "A man's heart is the muscle of his strength, not the arms and legs..
and not in his arms or legs, - see previous comment..
to that which his will clings he'll never depart - should this be a new sentence?
no matter how much reason begs!
He will live for a belief, he'll die for a cause,
this iron will's his greatest virtue,
he'll wrestle with demons vile without pause
for that which his heart holds as true - I like these 4 lines
And sacrifice all that he has on a whim - needs some punctuation to work
in fiery feats of integrity;
but truth is a phantom, ghastly and grim,
when his reasons are in-sanity; - why are you hyphenating "insanity"? are you trying to suggest the reasons are found in his sanity and are also insane? if so then I'm not sure this works here, it's too open to interpretation
See brothers fight brothers for forests and fields, - I like this line.
treasuring but greed and pride,
And women are raped "for the pleasures it yields",
for shame my soul flees to hide.
Yea the faults of all men are to be found in their hearts
alongside their greatest virtue,
for when passion is roused, reason departs
and men heed not what they do...

At the end here I find this jumps from being an observation on what men should be from what I would see as "high ground" to becoming a judgement on what you think they are when "roused". This seems to comes across as personal experience. I would suggest you keep the high ground at the end and use the possibility of "passion" being a man's downfall as a warning thus retaining the commentary distance that you start with.

As others have noted some of the same things above, I've tried make suggestions to help...