wheel of sun and moon and tutors
When casting an instant or sorcery, it goes:


Announce the spell and pay all costs
People can respond
Spell effect happens
Spell goes to graveyard


So in this case, you'd cast Enlightened Tutor, find the enchantment, shuffle your library and put then enchantment on top, and then try to put Enlightened Tutor in your graveyard. So you have your target on top of your library and Enlightened Tutor on the bottom.