Self-contained

Definitions: (1) having within oneself all necessary qualities; self-possessed; (2) functioning independently; self-sufficient; (3) formal and reserved in manner

Quotes:
• The power for creating a better future is contained in the present moment: You create a good future by creating a good present. — Eckhart Tolle [born Ulrich Leonard Tölle] (1948-) German-English writer
• The best artist has that thought alone Which is contained within the marble shell; The sculptor’s hand can only break the spell To free the figures slumbering in the stone.  — Michelangelo di Lodovico Buonarroti Simoni (1475-1564) Italian sculptor, painter, & architect