Homeopathy takes the body as a whole instead of independently working parts (hearts, lungs, brain etc.). You cannot prescribe correct homeopathy medicine for headache, for example, without taking into account all the mental and physical symptoms.
Though I am not going to start another controversial thread (about homeopathy), I just wonder why the mainstream medical science does not looks at human malfunctioning as a whole system. In other words why there are so many organ/tissues/functions specialists?
May be (with main stream medical science) we are on wrong path and have made things so complicated that it has impossible to consider the whole human body in one shot in any particular disease. Though we fully know that analyzing/treating the parts in a complex system won't take us too far.