While we must ignore pathological changes when choosing the remedy, yet a knowledge of true pathology is absolutely necessary.
1. We can only thereby understand the course and progress of the case.
2. We can thereby know the symptoms that are common to that special state, and hence those that are peculiar to the patient.
3. We also thereby know in certain diseases, or at certain stages of disease, that no matter how similar the symptoms produced by some remedies may appear to those of the patient, yet, owing to the superficial character of their action, they cannot prove curative.
For example, in pneumonia, in the stage of exudation, while the symptoms may apparently call for Aconite, we know that remedy cannot produce such a condition, and closer examination will reveal that some deeper acting remedy, such as Sulphur or Lycopodium, is needed.
4. Pathology enables us to decide, when new symptoms arise, whether they are due to the natural progress of the disease or of the action of the remedy.
5. We must clearly understand that it is the patient that is curable and not the disease, and without a proper understanding of pathology we are liable to err. Suppose a case of inflammation of a joint that has led to ankylosis. The suitable remedy will cure the inflammation, but will be powerless to break down the adhesions and surgical aid must be sought. The same holds good with regard to tumors, for when the patient is cured the tumor will cease to grow, and perhaps it may be absorbed, but very often it persists and must be removed by the knife.
6. Pathology also warns us that it is dangerous to attempt to cure certain conditions of diseases, such as advanced tubercular phthisis, or where foreign bodies are encysted near vital organs. In such cases nature can only cure by suppurating out such foreign substances, and the exhaustion entailed by such an operation is often fatal.