It is by no means certain that our individual personality is the single inhabitant of these our corporeal frames […] We all do things both awake and asleep which surprise us. Perhaps we have cotenants in this house we live in.

Oliver Wendell Holmes, Sr. (1809–1894) American poet, essayist, scholar

Article (1867-01), “The Guardian Angel,” ch. 3 “Antecedents,” Atlantic Monthly, Vol. 19, No. 91
    (Source)

Collected in The Guardian Angel, ch. 3 (1867).