The soul is subject to health and disease, just as is the body. The health and disease of both . . . undoubtedly depend upon beliefs and customs, which are peculiar to mankind.
MaimonidesFor it is said, "You shall strengthen the stranger and the dweller in your midst and live with him," that is to say, strengthen him until he needs no longer fall upon the mercy of the community or be in need.
MaimonidesAt times the truth shines so brilliantly that we perceive it as clear as day. Our nature and habit then draw a veil over our perception, and we return to a darkness almost as dense as before. We are like those who, though beholding frequent flashes of lightning, still find themselves in the thickest darkness of the night.
Maimonides