To this class belong all physicians who under certain circumstances employ certain remedies, of which they know from experience that under similar circumstances similar remedies have proved successful. This system may therefore be called “_Empiricism_,” and it constitutes the greatest part of modern therapeutics; for what little is known to-day of the physiological and therapeutic actions of medicine on the whole the result of observation, and not of a knowledge of the fundamental laws of nature which cause medicines to act as they do. Heat is a specific remedy for cold, and moisture for dryness; but even the very opposite remedies often have the same specific effect. Thus, for instance, the pain caused by an inflammation, and the inflammation itself, may be cured by cold as well as by hot applications to the inflamed part; for in one case the walls of the blood vessels contract, diminishing the quantity of the blood rushing to them, while in the other case these vessels dilate, rendering the rush of blood painless and easy. The specific action of chemicals is due to their chemical affinities (harmonies). Thus the invigorating action resulting from the inhalation of fresh air is caused by the affinity which Oxygen has for the Carbon in the blood, and by the life principle of the air upon the life principle in the body. Thus the tubercle-bacilli in the lungs may be destroyed by the specific action of certain gases, which, inhaled, form certain chemical compounds with certain elements contained in these micro-organisms, and thereby cause their destruction.[51] Everything in the universe takes place for a certain reason and has a certain specific action depending on certain conditions. If we know the laws and conditions, experience becomes a science; but where our science is blind, experience can be our guide. Like knows like. The physical senses only recognise physical things; but all visible things are an expression of soul, and what can we know about the _Soul of Things_, if we do not know that soul which is our own? There can be no motion, where there is no emotion to produce it, either directly or indirectly. All motions are manifestations of energy; energy is a manifestation of consciousness; consciousness is a state of the mind; mind is a vehicle for the manifestation of spirit; spirit is the “Breath” by which the world was _created_.