Most people say that she was healthy and that she was not crazy. Recently, people have tried to explain her visions through things like epilepsy, migraine, tuberculosis, and schizophrenia. None of these guesses have been greatly supported. This is because, even though seeing visions can be through different diseases, other facts of Joan's life do not agree with these ideas. Two experts who studied a teberculoma hypothesis in the medical journal "Neuropsychobiology "said: "It is difficult to draw final conclusions, but it would seem unlikely that widespread tuberculosis, a serious disease, was present in this 'patient' whose life-style and activities would surely have been impossible had such a serious disease been present." Ralph Hoffman, professor of psychology at Yale University, points out that visions, like ""hearing voices"" are not always signs of mental illness. He says that her religious inspiration was possibly a reason. However, he does not say any other reasons.