The Realms of the Sea, the Sky, the Earth & the Underworld are the places from which our remedies come & the properties of each are to be found in the remedies & the patients who need them. Understanding what those properties are & how they are likely to be expressed in a patient can help the homeopath to narrow down the group of remedies from which the required remedy can be chosen. The Realm is also a quick way of checking that we have understood the case & will throw up clearly any inconsistencies.