There are two main reasons why people do things: motive or malice.
Motive (noun) reason for doing something, e.g. police were unable to establish a motive for his murder
Malice (noun) the desire to harm someone; ill-will, e.g. I bear no malice towards anyone
Now with that first one, obviously Malice would be the motive if we were taking the definition at face value. But of course, nothing in this world should be taken at face value. Would you take anything at face value? A statement? Perhaps a person? Or a rumour? I wouldn't take any of those at face value; we're all made up of different experiences, rumours will always have another side and statements will always- always- have a motive.
So the definition we're going with for motive today is a valid reason for doing something. And that makes the motive extremely subjective, doesn't it?
There are two main reasons why people do things- motive and malice- the first being probably in the interest of the acting person or another (some one will benefit from the action, perhaps receive reparations, perhaps emotionally or perhaps a physical gain) but the other is perhaps in the interest of no one, not even the acting person. The latter, you see, bares no other purpose than to ruin someone or something. The latter, my friends, would motivate someone in order to maybe spur the lesser of two evils, it becoming in itself the greater evil. In itself becoming a malicious action, statement or person.
And no one likes malice, do they?