People who do not engage epistemology are not awere of the extant of our usage of iMOs. Hume was probably the first thinker that showed the we take for granted things we do not see. He demonstrated in his book ''An Enquiry Concerning Human Understanding''<ref>Hume D. (1748) An Enquiry Concerning Human Understanding</ref>, that cause and effect are not to be observed directly, yet people use them as though they are real enteties. ''God'' is iMO, and also ''The force of gravity'', and even the ''state'' is an iMO (Have any of you ever seen a ''state''?).

===Bush and Mosteller Learning Curve===