Castigation (from the Latin castigatio), chastisement (via the French châtiment), or chiding is the infliction of severe (moral or corporal) punishment. One who administers a castigation is a castigator or chastiser.
In earlier times, castigation specifically meant restoring one to a religiously pure state, called chastity. In ancient Rome, it was also a term for the magistrate called a censor (in the original sense, rather than the later politicized evolution), who castigated in the name of the pagan state religion but with the authority of the 'pious' state.
In Christian times, this terminology was adopted but roughly restricted to the physical sphere: chastity became a matter of approved sexual conduct, castigation usually meaning physical punishment, either as a form of penance, as a voluntary pious exercise(mortification of the flesh) or as educational or other coercion, while the use for other (e.g. verbal) punishments (and criticism etc.) is now often perceived as metaphorical.
Self-castigation is applied by the repentant culprit to himself, for moral and/or religious reasons, notably as penance.
-Wikipedia Online Encyclopedia
I find myself returning over and over to the truth that it is a punishment, which would mean that it is issued in direct result of a sin, often willingly by the sinner himself... and I cannot understand why I did last night what I did, or if it were even the right thing to do. I broke my own heart deliberately and completely and I cannot find the pieces because they are so far away, and I let down the trust and confidence of my best friend, lying to her when I said that I could, indeed, remain her friend and give her my continued support.
But it hurt so bad. It was unbearable. And now it is so much worse because, for once, I woke up knowing I can never go back and tell her I'm sorry, that I didn't mean it, and that now I have complete control over myself, and that I would lose a limb to fire and not take back my word. I have lost myself my best friend, and deliberately, too, with forethought and unyielding execution. I have trampled myself into the dust, removed from myself my most constant and reliable shoulder I have ever had to lean upon, severed myself from my most valued confidante, the one with whom I have no secrets and who didn't mind my mistakes.
I wish I had not done it. I wish I had kept on alone, sticking through the pain like I always have, holding to that slim hope of a future when everything was the way I dreamed it could. I need her more than I ever knew.
On a parting note, I find it ironic how the only other link from Wikipedia's article on "castigation" was for "capital punishment"...
That's all there is.