Sentence:  The problem in the policy officer 's <WSD>mind</WSD> thus begins to take shape as a galaxy of utterly complicated factors - political , military , economic , financial , legal , legislative , procedural , administrative - to be sorted out and handled within a political system which moves by consent in relation to an external environment which cannot be under control . 
Meaning of the word marked with <WSD> tags:  that which is responsible for one's thoughts and feelings; the seat of the faculty of reason