Some Clues about the Elemental & Fundamental Mentality creating all Existence:

Just Modes of Conceptualization:
Time and space are not conditions in which we live, but modes by which we think... Albert Einstein.
Time and space are not (objective) things, but (mentally imposed) orders of things... Leibniz

Just Cause and Effect:
Intentional action (karma = Kamma) is decisive information about to do this & not that.
This information creation reduces the universal thermodynamic entropy (degree of disorder)...
This newly created order limits, restricts & thus affects the future evolution of the universal system.
The probability of certain future events happening have thereby been increased, while the probability of other future events have been reduced.
Any intention by any being thereby modifies and narrows the potentiality of the universe - seen as a giant network of cause and effect - which then naturally later falls out and manifests as another - now intentionally changed - actuality...
The moral efficacy of kamma = karma = action is therefore not a religious metaphysical postulate, but a simple and ultra - basic inevitable consequence of the mentally derived nature of the universe itself...
Morality is thus a natural Law on par with gravity:
Do good and get pleasure (Sukha)...
Do evil and get pain (Dukkha)...

ORIGIN
Intention always comes first
Intention is of all states the primer
By intention are all things initiated
By thought of mind are all phenomena formed
So - if with good intention one thinks, speaks or acts
Joy surely follows one like the never - leaving shadow
However!!!
- if with evil intention one thinks, speaks or acts
Pain certainly follows one like the wheel follows the car.

Dhammapada 1 + 2