The most immediate fact of man's consciousness is the assertion "I am life that wills to live in the midst of life that wills to live." Affirmation of life is the spiritual act by which man ceases to live thoughtlessly and begins to devote himself to his life with reverence in order to give it true value. To affirm life is to deepen, to make more inward, and to exalt the will to live. At the same time the man who has become a thinking being feels a compulsion to give to every will to live the same reverence for life that he gives to his own. This is the absolute, fundamental principle of ethics, and is a fundamental postulate of thought.
In his search for an answer to the problems posed by what was to him the obvious decline of western civilization, Albert Schweitzer was not prepared to give up the belief in progress, which is so much taken for granted by people of European descent. Rather, he sought to identify why this "will to progress" was seemingly going off the rails and causing the disintegration of European civilization.
By itself, the affirmation of life can only produce a partial and imperfect civilization. Only if it turns inward and becomes ethical can the will to progress attain the ability to distinguish the valuable from the worthless. We must therefore strive for a civilization that is not based on the accretion of science and power alone, but which cares most of all for the spiritual and ethical development of the individual and of humankind.
Standing, as all living beings are, before this dilemma of the will to live, a person is constantly forced to preserve his own life and life in general only at the cost of other life. If he has been touched by the ethic of reverence for life, he injures and destroys life only under a necessity he cannot avoid, and never from thoughlessness.
Ethics is nothing other than Reverence for Life. Reverence for Life affords me my fundamental principle of morality, namely, that good consists in maintaining, assisting and enhancing life, and to destroy, to harm or to hinder life is evil. Reverence for Life says that the only thing we are really sure of is that we live and want to go on living. This is something that we share with everything else that lives, from elephants to blades of grass - and of course, every human being. So we are brothers and sisters to all living things, and owe to all of them the same care and respect, that we wish for ourselves.