Remedies are divided into groups for several reasons. One is for ease of study and memorization. Another reason is based on philosophical assumptions. The reasoning is that if you put enough remedies together that have a similar physical attribute you will see a similar medicinal effect that can be used advantageously. Because people like to look for associations in order to understand the nature of the healing action of remedies, homeopaths have explored many groupings in order to shed light on our understanding of the impenetrable mechanics of healing.
There are two directions we could take to verify the correct way to group remedies. One, a top down approach, is to understand how remedies heal and then group the remedies that heal similarly together. We don’t know how remedies heal and it doesn’t look like we will know very soon although we have plenty of theories. You could choose one theory and apply a categorization of remedies to see if it fit in but it would be mostly an academic exercise.
Another way to verify a correct grouping is to go from the bottom up. We group a bunch of possibly related remedies together according to their relationship to an understood system and then see if it holds up to scrutiny. If it doesn’t then perhaps we end up with a nice mnemonic system. The Doctrine of Signatures has an attractive system in that it is easily understood and useful for recalling remedies’ attributes. People assume that the accumulation of memorization aids over the centuries is enough to corroborate the truthfulness of the system but it falls apart once you try to expand it to other remedies.
The bottom up approach is what people use allying themselves with anatomy, botany, chemistry, psychology and even astrology to create new and ingenious groupings. And as with any study where there is an unknown, people will more likely listen to someone marketing themselves with a new approach so the more unusual systems are usually what gets talked about in the popular press.
To validate systems by borrowing accepted concepts and create more modern sounding explanations, some shy away from the simplistic idea of groups and invade the more mystical world of Karl Jung for use of the word archetype. The use of the word archetype is consistent with how homeopaths used to talk about the genius or the keynote of the remedy. But there is a layer of metaphysical philosophy that usually is added for justification in creating a modern Doctrine of Signatures. They are all trying to figure out why homeopathy works but not a lot of progress has been made.
Thought question: What prevents us from believing that there is no difference between taking a remedy made from the venom of the cobra and practicing a yoga position based on the cobra?