Effect is determined by the nature of cause. So the result of action is determined by the nature of action. Actions have no existence apart from the mind. Action is only an extension to the thought processes of the mind. Therefore action is determined by the nature of your mind. The nature of your mind is determined by your mental tendencies. Hence it is necessary to take into consideration the role of the human mind and its inherent mental tendencies to understand the workings of karma, the law of cause and effect. We find this association of karma with mental tendencies in the Vedas:
You are what your deep, driving desire is. As your desire is, so is your will. As your will is, so is your deed. As your deed is, so are the consequences thereof.
The deep driving desires mentioned in the verse here refer to a subtle form of desires and inclinations (vasanas) that make up a part of your mental tendencies (samskaras). They are the primary force among mental tendencies which motivates and compels you to engage in various actions in life. Mental tendencies sprout as thought-waves (vrittis) in your conscious mind. Each thought-wave vibrates at a specific frequency and gives rise to a certain mental experience. They can be perceived as sensations, attractions, intentions, desires, notions and ideas in your conscious mind. They influence the mental climate in which you choose your action. Your actions are generally inclined towards thoughts or desires that are more dominant in you.
However a desire by itself does not become an action without your approval. A desire-thought can create a powerful agitation in your mind but it can only manifest into action when it is transformed into will. It becomes will when you identify, approve and own a desire. Will has direction and motivation to it. Thoughts that you do not identify with will ultimately dissipate.
Will wanes or waxes when desire decreases or increases. The changes in the nature of your will changes the effect of your actions. Your will is also constantly strengthened or weakened by other thoughts. Most of the time, the will is weakened when you are distracted from your purpose and when you are overwhelmed by emotions and beliefs that are contrary to your desire. Opinions and expectations from other people can exert additional mental pressures and may not empower your will if their intentions are not aligned to yours.
In a court case, a person committing murder in self-defence is judged differently to a person committing murder with malicious intent. The nature of the mind is the differentiating factor here. This is also true in the functioning of the law of cause and effect. The consequences of the same action performed by two persons having two different frames of mind will be different.
The thoughts with which you identify shape the force and nature of your actions. Many times you identify with a bundle of thoughts that are a mix of desires, emotions, intentions, assumptions and other mental factors that can even be conflicting with each other and thus invite a different result from what is expected. It is certainly not easy to remain focused on a desire in its pure form without the interference of other emotions. Therefore it is important to be clear about what you want, to have purpose in your desire, to create priorities and to be alert to conflicting thoughts and emotions in order to ensure they don’t knock you off course in your effort. As the thought vibration, mental force and will shaping your actions so the consequences thereafter.