Where Do Our Thoughts Arise From?
A large percentage of your thoughts are determined by what you perceive through your senses. Everything you see, listen to, smell or feel causes some reaction or other in your mind. See how your senses are connected to your mind. Any negative thing that they pick up or produce will disturb the mechanisms of your mind. If you want to have spiritual peace, then use your eyes, ears and mouth with caution.

Other thoughts arise from the impressions that have been recorded in your subconscious (identity, personality and/or character), and they may be positive or negative. The negative ones are often due to deep marks and/or habits caused by past events or experiences, and also everything that is deeply established and settled in your inner self (belief system).

The sight and hearing senses are those used most in human beings, with as much as 80 per cent of the information we receive being processed through these two senses. We should always be on the alert to ensure that nothing negative enters these two doors that might contaminate our mind. We need a guardian to ensure that does not happen. This guardian is our intellect, the part of our conscience that contains the wisdom (knowledge) and capacity to discriminate between right and wrong, beneficial and harmful, truth and falsehood.

Observing the mind, we can be aware of the thought patterns that originate in our subconscious. It is important to understand that "you" are separate from "your" thoughts. You are not your thoughts, but your thoughts are created by you.
With regular practice of meditation you will be able to choose at any time which thoughts you are going to focus your attention on and which ones you wish to disregard.