Nothing can rise to heaven but what has descended from it, we can only by overcoming that which is false render ourselves receptive for that which is true. _Eckhart_ says:—“Divine Wisdom is to God what the sunlight is to the sun; it is one with Him, a necessary activity, a never dying fountain, having its source in the heart of God.” This brings us back again to a _religious_ basis (if we are permitted to use this ill-treated and misunderstood term), and to the necessity that he who makes it his profession to employ the laws of nature and treat the body of man should know the position which man occupies in nature and the position which nature occupies in regard to the origin from which it originates. This science requires not mere words, but self-knowledge. Wisdom can only be taught by Wisdom itself; but a science based upon a recognition of truth disperses the clouds which prevent the light of the truth from entering into the heart and becoming incorporated and manifested in man. III. THE FIVE CAUSES OF DISEASE. If we inquire from modern medical science: What are the causes of diseases? we shall probably be answered: 1. _Age._ 2. _Heredity._ 3. _Intermarriage._ 4. _Sex._ 5. _Temperament._ 6. _Climate and locality._ 7. _Town or country._ 8. _Hygienic conditions._ 9. _Occupation._ 10. _Air._ 11. _Previous disease._ 12. _Mental and moral conditions._ 13. _External physical conditions._ 14. _Poisons._ 15. _Temperature._ 16. _Diet._ 17. _Epidemic disease, contagion, malaria, parasites and growths._[29] We will forbear to pass any remarks upon this classification of the causes of diseases, which merely enumerates certain conditions in which diseases may arise, and we will pass on to the classification of the causes of diseases given by Paracelsus; but as this subject has already received attention in a previously published work on the doctrines of Paracelsus[30], the following is intended merely to supply additional food for thought. Paracelsus says: “_All diseases have a beginning in either of the three substances;[31] Salt, Sulphur, or Mercury_; which means that they may take their origin either within the kingdom of matter, within the realm of the soul, or in the sphere of the spirit. If body, soul and mind are in perfect harmony with each other, no disharmony exists; but if a cause of discord arises in either one of these three planes, it communicates itself to the rest.” Before proceeding further we will inquire about the nature of these _three Substances_: