The turbid well-spring and corrupt source 1 is the disease of self-love. Those afflicted with it are blinded, incapable of seeing the undeniable truth of their desperate situation; they lose sight of the correct path. Just as one who is physically ill may find food and drink a source of pain, the same is true with the spiritually ill, those who by nature are proud. The more knowledge of Torah they amass and the further they progress in mitzvah observance, the more important they consider themselves and the more arrogant they become.
Every disease has its malignant source, its core that gives it the power to grow and spread, and to wreak havoc on the body of the patient. The germ of the soul-sickness we described is ignorance of the illness. The person who knows that he is sick will seek means to be cured; he will expend all his resources to regain his health. If he lacks the means, then he will seek assistance from others sympathetic to his plight. But one who is unaware of his illness will not seek a cure, and will ultimately succumb.
