All living beings from bacteria to humans are made of cells. At the simplest level life is a network of chemical processes that regulate themselves. Cells adjust energy repair damage and respond to the environment automatically. There is no inner controller making choices. These processes unfold because chemistry requires them to.

As organisms became more complex some cells specialized and formed nervous systems. The nervous system coordinates the body across space and time. From this coordination the mind appears. The mind is not a separate entity. It is a pattern created by millions of neurons interacting with one another.

The mind has three primary functions. Sankhya names these functions as manas ahankara and buddhi. Manas handles sensory input and simple processing. Ahankara creates the sense of I and mine and generates ownership. Buddhi interprets situations forms judgments and provides discernment. Together these form citta the full mental field and they all belong to the field of nature where all mental activity arises.

The mind does not control the organism. It narrates what the organism is already doing. It weaves perception memory and emotion into an inner storyline. This story produces a self model which helps the organism predict danger stay safe and function in social groups.

In simple animals the self model is minimal. In humans it becomes highly detailed. Ahankara generates stories about who we are what we want and how others see us. These stories are practical tools for living in a complex social environment.

Behind these stories is the brain’s predictive machinery. The brain constantly tries to reduce surprise. It guesses what will happen next and adjusts when predictions fail. What feels like free will is often the mind explaining its own reactions after they have already unfolded.

Why do certain thoughts emotions and preferences appear. Sankhya explains this through samskaras impressions left by past experience. When a reaction or emotion repeats an imprint is stored in the mind. Over time these impressions influence how future thoughts and emotions arise. Modern psychology calls this conditioning. These samskaras shape the movements of citta just like grooves shape the flow of water.

Up to this point everything described belongs to the field of nature. Biology psychology memory habit conditioning personality and every story in the mind are natural movements. But there is something in direct experience that does not behave like these movements. It does not come and go. It does not change when thoughts or emotions change.

It is the simple fact that experience is known. A thought appears and it is known. A feeling rises and it is known. That knowing does not take effort. It does not begin with each thought. It is quietly present before during and after every experience.

Sankhya calls this knowing presence purusha but in simple terms it is the witness. The witness is not a thinker or a doer. It does not push thoughts or stop them. It does not choose emotions. It does nothing. It simply knows. You can see this directly. A thought comes without your permission. A feeling comes without your control. Yet the knowing of them is effortless. The knowing remains the same while the content changes.

This is the essential distinction. Everything that moves changes reacts or transforms belongs to nature. The knowing of those movements is the witness. Nature is active. The witness is still. Nature changes. The witness does not. Nature produces thoughts feelings impulses and preferences. The witness simply knows them.

Once this is seen directly a new clarity begins. Sankhya calls this viveka the experiential recognition that the witness is entirely different from the movements of the mind. Viveka is not an idea or belief. It is the moment to moment seeing of what is the witness and what is the natural mind. As this clarity grows life becomes lighter. Thoughts lose their weight because they are seen as natural processes rather than personal burdens.

From this recognition effortless existence begins.