From the Catholic Encyclopedia:
"Positive and direct suicide perpetrated without God's consent always constitutes a grave injustice towards Him. To destroy a thing is to dispose of it as an absolute master and to act as one having full and independent dominion over it; but man does not possess this full and independent dominion over his life, since to be an owner one must be superior to his property. God has reserved to himself direct dominion over life; He is the owner of its substance and He has given man only the serviceable dominion, the right of use, with the charge of protecting and preserving the substance, that is, life itself. Consequently suicide is an attempt against the dominion and right of ownership of the Creator."
For someone to go to hell, they must have mortal sin weighing on their soul. For a sin to be mortal, it must be an action contrary to the eternal law preformed voluntarily and not affected by outside forces like habit or mental disorders. In most cases, suicides are committed when someone is under severe mental anguish and as such doesn't act rationally. In such a state, the sin cannot be seen as voluntary, because in a normal mental state the actor most likely would not have committed the sin.
I attended Catholic school for 12 years, this stuff is beaten into my brain.
From the Catholic Catechism:
2281 Suicide contradicts the natural inclination of the human being to preserve and perpetuate his life. It is gravely contrary to the just love of self. It likewise offends love of neighbor because it unjustly breaks the ties of solidarity with family, nation, and other human societies to which we continue to have obligations. Suicide is contrary to love for the living God.
2325 Suicide is seriously contrary to justice, hope, and charity. It is forbidden by the fifth commandment.
This confirms that suicide is, indeed, a sin.
It would classify as a mortal sin for a Catholic--ie: condemns you to hell after death unless absolved in that it:
1. is a grave matter
2. the party knows that it's a sin and that it is a grave matter
3. it is deliberate.
(the three standards by which sins are graded as venial or mortal as per Catholic doctrine)
And since you DIE as a part of successful suicide, it cannot be absolved since the sinner him/herself must seek absolution.
Suicide is a sin, yes, but that doesn't guarantee that it is a mortal sin... there are other factors at work too.
On the contrary, most suicide is the result of a process of evaluation. It's not a spur of the moment, instinctual act. It is the culmination of aforethought and planning. It is the end result of a line of reasoning, making it inherently rational.
I think you're thinking 'rational' like 'being reasonable'; the opposite is "not being reasonable", which is the most common usage of the word "irrational".
But in terms of philosophy--of which theology is a branch--most suicide is indeed rational.
Just because the end action is bad doesn't mean it wasn't reasoned.
What I was trying to get at was that suicide doesn't automatically send you to hell. There are cases where it's classified as a venial sin (because of mental illness), and even other cases where it's not a sin at all. (throwing yourself in front of a train to save someone knowing full well that you're going to die if you do so)
[Edited by Latiosmaster47, 10/28/2009 5:15:51 PM]