Chapter 10, Footnote #18
Habit, only fictitious
Strictly speaking, habit, being but a fictitious entity, and not really any thing distinct from the acts or perceptions by which it is said to be formed, cannot be the cause of any thing. The enigma, however, may be satisfactorily solved upon the principle of association, of the nature and force of which a very satisfactory recount may be seen in Dr. Priestley's edition of Hartley on Man.