(Just to get this out of the way- I'm Vajrayana, so that's the perspective I'm speaking from, though... I'm American, so not SO much the Vajrayana perspective, hahaha)
I've heard a lot of teachings about intention, and right intent and things like that, and I've also read a bit about negative intentions and thoughts. I'm not sure if this is correct, but I believe I've read that you can generate negative karma even from negative intents or thoughts? As an act is composed of the intent, the action, and the aftermath, I think it's entirely possible.
What I'm really wondering has to do with the opposite- can you generate good karma merely with good thoughts and intentions? I think it would be a small amount opposed to a full act, but... can you? I thought about this because I had gotten a recording of someone chanting white tara stuck in my head, so in my head, I kept replaying it, much like a song stuck in your head usually does. I've heard attained masters can merely think a mantra and the full effect will be taken, but is there any merit or, at least, benefit to others merely by thinking about it? To be on the safe side, I've begun singing along with the mantra playing over and over in my head.
Much thanks on your input,
PS: If you could in replying, tell me any sources you may have for your thoughts. Merely thoughts and opinions alone are in fact helpful, but having the words of an actual teacher speaking on the subject would be great for clarification.
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OM TARE TUTTARE TURE SOHA
"The world is dark when you're depressed; your thoughts have the power to invent your world." -Courage Wolf
"It is more important to be kind than to be right."
(I acknowledge I do not follow the quote above this, that is why it is there! so I will be reminded every time I post!