Quicquid ex ratione conamur, nihil aliud est quam intelligere nec mens quatenus ratione utitur, aliud sibi utile esse judicat nisi id quod ad intelligendum conducit.
English (Elwes 1883)
Whatsoever we endeavour in obedience to reason is nothing further than to understand; neither does the mind, in so far as it makes use of reason, judge anything to be useful to it, save such things as are conducive to understanding.
Modern English
Whatever we strive for under reason's guidance is nothing other than understanding, and the mind, insofar as it uses reason, judges nothing to be advantageous to itself except what conduces to understanding.