The word remedy should include all adjuvant treatment used in connection with a proved drug. We will, however, exclude surgery, but with this understanding, viz., that the proved drug is often of equal importance with the instruments in many surgical cases, especially in the preparatory and after treatment. The effect of heat and cold, of position, of diet, of exercise, etc., must all be taken into consideration when we select the remedy, because they are our modalities of the proved drug. We will define remedy as used by Hahnemann in our sentence as: Any substance which when given to a healthy person has the power of causing variations from the normal, of any tissue, or of any function of a tissue or organ. By proved we mean that a drug has been administered to a healthy person and the effects carefully observed and properly recorded. These manifestations we call symptoms of the remedy. Hence we speak of the symptoms of a disease, also of the symptoms of a drug or remedy. In order to facilitate matters we will use the same definition and classification of a drug symptom that we did of a disease symptom, viz., three essentials, four or more causes. However, we use the word characteristic instead of pathognomonic when we wish to designate a drug symptom of highest rank. I want to impress more forcibly upon you the first essential – location. I give it the first place in my drug proving, in my study and teaching of remedies, also in my use of remedies. To me, the “elective affinity of drugs” is the greatest corollary of our great law. Let me use the words of one of our best students and prescribers on this point. He says: “The action of a drug is the action of a living thing which can think and act.” Let me state a few facts as evidence of the truth of the above statement. Take a seed of aconite, podophyllum and gelsemium and plant them in the same soil. From the time the first shoot appears from the seed they receive the same sunshine, the same dew and rain, and the same air and elements from the soil. Yet every one selects from the above just what it needs to mature itself and remains aconite, podophyllum and gelsemium to all time. Every plant is composed of cells, every cell of atoms and ions. The ion or atom has all the properties of the cell. Every cell has all the properties of the entire plant. What is true of plants is true of minerals, of acids and also of animal drugs which we prepare and use as remedies. We will show later on that the same something (we used to call it active principle of a drug) which can select from its surroundings just what it needs to mature, perfect and perpetuate itself, also selects some definite ion, atom, molecule, cell, tissue or organ of the living human body upon which it expends its force. Thus we observe that the something of a remedy selects some tissue or organ through which to manifest itself.
– American Institute of Homoeopathy,