What do we mean by death? Though we have theories, speculations, and there are certain observable facts, death is still the unknown. Whatever we may know about it, death itself cannot be brought into the field of the known; we stretch out a hand to grasp it, but it is not. Association is the known, and the unknown cannot be made familiar; habit cannot capture it, so there is fear.
Commentaries On Living, Series II
Chapter 14 'The Fear Of Death'