During the last decade there has been increasing interest in combining veterinary and human medicine, mainly in the areas of vaccination and the eradication of zoonotic and vector-borne diseases. Although the roots of this "One Health-One Medicine" approach can be found in ancient Egypt and Greece, the roots of the philosophy of "one medicine" have not been so thoroughly discussed. In this paper I will analyse some ideas that could unite veterinary and human medicine, from Rudolf Virchow and Calvin W. (...) Schwabe. Both are recognized as important theoretical founders of the philosophy of one medicine. I will also further develop these thoughts to meet some of the discussions taken place today. (shrink)