Misunderstood Homeopathic Concepts: What are Miasms?

Miasm are a method of classification. In the case of homeopathy, the similarity of the symptoms of a remedy to the disease classifies both at the same time. Like cures like. So Belladonna belongs to the acute miasm, right? One takes belladonna not because of the acute miasm but because of the similarity of it to the illness. Therefore, one cannot clear a miasm because the miasm is an abstraction. One cannot take Carcinosinum to clear cancer. Though I know some people do that it does not make sense at all once we understand that what a miasm is.
Lastly, people know three miasms but today I could not work with less than 18 miasms. There is a very practical aspect to that number. The table of elements has 18 columns that represent 18 stages or 18 miasms.