Legitimate

Definitions: (1) conforming to established rules, principles, or standards; law-abiding; (2) applied agreement to the precepts of reasoning; logical; valid; (3) genuine; real; justified <a legitimate complaint>

Quotes:
• To cherish what remains of the Earth and to foster its renewal is our only legitimate hope of survival. — Wendell Berry (1934-) American writer
• No individual has any right to come into the world and go out of it without leaving behind him distinct and legitimate reasons for having passed through it. — George Washington Carver (1864–1943) Agricultural scientist