Life is an instinct for growth, for survival, for the accumulation of forces, for power.

Life, on this view, is not mainly a search for comfort or happiness but a push outward: to grow, to endure, and to gather strength. Nietzsche treats living things as driven by an inner pressure to expand their capacities rather than simply to stay safe. "Power" here does not mean domination over others so much as the feeling of becoming more capable, more alive, more able to shape one's circumstances.

The thought rests on his idea of the will to power, which he set against the Christian and Schopenhauerian traditions that prized pity, renunciation, and the quieting of desire. For Nietzsche, a way of thinking that praises weakness or self-denial works against life's own tendency. The wording differs between English translations, but the idea closely matches what he says in several of his later writings.

In practice, someone might stop asking whether a choice is comfortable and ask whether it makes them stronger. A person stuck in a job they have outgrown could take on a demanding project, learn a new skill, or have the difficult conversation they have been avoiding, accepting some strain because it builds capacity.