Albert Schweitzer, a theologian, philosopher, and physician, developed the ethical principle of 'Reverence for Life' (Ehrfurcht vor dem Leben). This philosophy, central to his work as a medical missionary in Africa, emphasized respect for all living beings and influenced modern environmental and animal welfare ethics. While Gandhi, King, and Radhakrishnan promoted non-violence and compassion, Schweitzer specifically formulated reverence as a universal ethical principle.