Via late Latin from the Greek for 'the latter the former'; in rhetoric a figure of speech such as “he liked bread with his butter” where what should normally come first comes second. The expression is similarly used in philosophy to describe an argument where a conclusion is fallaciously taken as a premise.
Editors. "Hysteron Proteron". The Literary Encyclopedia. First published 01 November 2001
[http://www.litencyc.com/php/stopics.php?rec=true&UID=529, accessed 27 November 2015.]