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).