Buddha first establishes the fact that evil exists; then he inquires why it exists and must always exist; he attempts to prove that it can and ought to be annihilated, and finally he occupies himself with the means of this annihilation.[432] He who will ascertain truth and acquire freedom from evil, has first to convince himself that evil exists. Evil is birth, sickness, the weakness of age, the restlessness and torment of our projects and efforts, the inability to attain what we strive for, the separation from that which we love, the contact with that which we do not love. In this world of existence all is vanity. Happiness is followed by misfortune; even the happiness and power of kings flows away more rapidly than running water.[433] Mutability is the last and worst evil; it is the fire which consumes the three worlds.[434] Birth is changeable and worthless, for it leads to death; youth, for it becomes age; health, for it is subject to sickness. All that exists, passes away. This ceaseless change is bound up with pain and sorrow. Childhood suffers the pain of weakness; youth is impelled by desires which cannot be fulfilled, and which cause pain if unfulfilled. Age suffers the pain of decay and sickness, and of death; with death begins a new life through regeneration to the same or even greater torments. To this evil of mutability, and consequently to pain, all living creatures without exception are subject. Evil and pain are universal; men are destined to lose what is dearest to them; and animals are destined to be eaten by each other. From the knowledge that evil exists, that all living creatures are subject to evil, follows the truth that men must strive to liberate themselves from evil.