The purpose of this work is to show and integrate distinct points of view used to study the conscience. Among these are popular, psychological, etological, evolutionary, pathological and neuroscience concepts. It is emphasized and brought up the fact that the anthropocentric vision has alienated other animals from the capacity of being conscientious, although there are multiple grounds that allow recognizing the presence of conscience in species other than human beings. It is concluded that conscience may be understood at various levels, but that it is necessarily a product from the activity of the nervous system and that there is still a long way to understand it.