Of the association of ideas (Hume 2007 )
Though it be too obvious to escape observation, that different ideas are connected together; I do not find, that any philosopher has attempted to enumerate or class all the principles of association; a subject, however, that seems worthy of curiosity. To me, there appear to be only three principles of connexion among ideas, namely, resemblance, contiguity in time or place, and cause or effect. (Hume 2007:16)
HUME, David. 2007. An enquiry concerning human understanding. Oxford: Oxford University Press.