Charles Darwin (1809-1882) suffered from a chronic illness that, throu
ghout much of his adult life, impaired his functioning and severely li
mited his activities. The writings of this famous scientist as well as
biographical materials indicate that he probably suffered from an anx
iety disorder. His symptoms, when considered individually, suggest a v
ariety of conditions, but taken together they point toward panic disor
der with agoraphobia. This diagnosis brings coherence to Darwin's acti
vities and explains his secluded lifestyle, including difficulty in sp
eaking before groups and meeting with colleagues.