A Brief Concordance to Book XI

The word imagination is used (in some form or another) at lines: 45, 252
The word “reason” is used at lines: 43 (“intellectual power”), 70, 83 (“logic”), 86, 123
The word “nature” is used at lines: 31, 99, 138, 146, 162, 178, 213, 255, 393
The word “mind” is used at lines: 46, 118, 128, 151, 169, 188, 263, 270, 369