Question: I want to know how *suicide* is viewed in Buddhism. I know that it is not viewed positively, but I want to know why. Is it because it brings grief to others? Is that the only reason? Or there is something else..? 
I think that if you die happily in a calm state because you wish to, there is no negative energy within you.. so I don't understand why suicide is such a bad thing. *(the reasons I think are the grief that will bring to the family and that one's negative energy will linger)*

Buddhism also varies among countries and cultures (I'm from the East Asia), but I believe it all began with the core teachings of Buddha and I just want to learn his teachings.

Thank you.

Answer: 
Possible list of reasons for not condoning suicide:

* You are intentionally taking a life which is breaking Sila and Vinaya
* It bring social problems like misery to loved ones and oftens dependents
* The act is done with negative mental state hence does not lead to beneficial rebirth in the next life.
* Based on the view of extinction or nihilism which is unskillful

More on this see:

* Introduction to [Chann’ovāda Sutta](http://www.themindingcentre.org/dharmafarer/wp-content/uploads/2009/12/11.12-Channovada-S-m144-piya.pdf) by Piya Tan
* [Death: An early Buddhist perspective](http://www.themindingcentre.org/dharmafarer/wp-content/uploads/2013/04/48.2-Death-An-early-Buddhist-perspective.-piya.pdf) by Piya Tan
Suicide is the result of hatred towards yourself, perhaps others or a thing (sickness). Hatred is an unwholesome mental state which will result in a birth in a lower realm. 

This is a disputed subject in Buddhism. There is an extended discussion at this link: <https://dhammawheel.com/viewtopic.php?f=13&t=27879&hilit=>