We shall at once see that the common symptoms are those that appear in all the cases of measles, that you would expect to find in measles. It would be strange to have measles without any rash; that would be peculiar. We know that the absence of rash is a striking state of affairs and means trouble, and is peculiar. Either it is not measles, or the absence of the rash is a serious state.
Suppose it is a fever. That patient has intense heat, an ordinary fever coming on in the afternoons and running through the night, with hot hands and feet, high temperature, dry tongue, etc. What would you say concerning the presence or absence of thirst? You would say it is common if he has thirst, because almost anybody who has fever would want water. Nothing is so natural to put fire out with as water, and the absence of thirst in fever is strange, is rare and uncommon, peculiar and striking.
You would ask yourself at once, is it not strange that he does not have thirst with such a high temperature? You at once strike to the remedies that are thirstless. You would not think of hunting up a remedy that has thirst. The absence of the striking features of disease constitutes a peculiarity that relates to the patient. Well, then, that which is pathognomonic is common, because it is common in that disease, but an absence of the pathognomonic characterizes that peculiar disease in that patient, and therefore means the patient, and in proportion as you have that class of symptoms just in that proportion you have things that characterize the patient, and the specific remedy for the patient will be the simillimum.
It is necessary to know sicknesses, not from pathology, not from physical diagnosis no matter how important these branches are, but by symptoms, the language of nature.
A homoeopathic prescription cannot be made on pathology, or morbid anatomy, because provings have never been pushed in that direction. Pathology gives us the results of disease, and not the language of nature appealing to the intelligent physician. Symptomatology is the true subject to know. No man, who is only conversant with morbid anatomy and pathognomonic symptoms, can make homoeopathic prescriptions.
In addition to diagnostic ability he must have a peculiar knowledge; that is, he must be acquainted with the manner of expression of each and every disease. He must know just how each disease expresses itself in language and appearance and sensations. He must know just how every remedy affects mankind in his memory and understanding and will, because there are no other things that the remedy can act upon as to his mind, and he must know how the remedy affects functions because there are no other ways in which the remedy affects the body of man. Now, if he knows how diseases express themselves in signs and symptoms, then he knows what constitutes an individual disease a little different from all others.
It is the peculiar way that the same disease affects different patients that makes the symptoms strange, peculiar and rare. That which is pathognomonic in the remedy is that which you will study out most, because it is that which is related to the patient. Such is the state of mind that the homoeopathic physicians must keep themselves in order to begin this study, and when they have begun to think in this way they can then study the symptoms of the disease as to grade.