Reasoning, logic (9)
I believe the answer is:
rationale
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">reasoning</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >'<span class="explanation-format__original">logic</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for rationale that I've seen before include "justification" , "Motivation" , "Good reason" , "The logical basis of some thing or action" , "grounds?" .)