The German philosopher Immanuel Kant (1724-1804) suffered, since his fourties, from a migraine with aura which showed a significant exacerbation in his seventies, coinciding with the onset of symptoms of a senile dementia of Alzheimer's type. Recorded symptoms of Kant's migraine include recurrent scintillating scotomas, one episode of diplopia, two episodes of complete amaurosis and frequent headaches described as oppressions of the head. The said symptoms of Kant's migraine can be traced not only in his letters and in accounts of his contemporary biographers, but also in the philosopher's published work.