Symptoms are the working units of the doctrine.
This is in striking contrast to orthodox medicine where objective findings, results of X-rays, ultrasounds, CT scans, laboratory findings and other tests, will determine further management of the patient. An American homeopath Constantine Hering published his work 'The Guiding Symptoms of Our Materia Medica' in ten volumes. Another homeopath, T.P. Allen, compiled 'Encyclopaedia of Pure Materia Medica' in eleven volumes. Participants have used no objective tests to compare the results, only compilation of subjective feelings. The slogan 'Similia Similibus Curentur' became primarily important as the battle cry of homeopathy for public consumption.