There are 2 fundamental ways by which we can engage a mind.
Propter Psukhē – We can go through the mind and engage it on a conscious level.
Circum Psukhē – We can go around the mind and engage it as to what it is unaware.
So that if we’re thinking of an interview, of which the answers are directly relevant, with no hidden purposes, so that on the face of it, the questions being asked are the questions of import, we would call it propter.
But if we were thinking of an experiment, as to which the subject were unawares of the implications, and the motivations of the experimenter, we would call it circum.