The Jedi Order were the guardians of peace in the Star Wars galaxy; they defend and protect all sapient life, never attack. The Order consisted of polymaths; teachers, philosophers, scientists, engineers, physicians, diplomats, and warriors. The Jedi moral value system viewed purity of thought and detachment of emotions as essential to enlightenment. Jedi philosophy emphasized self-improvement through knowledge and wisdom, adherence to slave morality, and selfless service through acts of charity, citizenship, and volunteerism; this ideology is a recurring theme in the Star Wars universe. The Jedi denounce emotions as the root cause of mortal suffering; they believe fear, anger and love cause sentient beings to lash out in conflict and impede rational action to do what is objectively correct action. Their traditional weapon is the lightsaber, a device which generates a blade-like plasma powered by a Kyber crystal or other focusing item, ex. Krayt Pearl.