One of the purposes of the intellect is to "assign value" to various things, hopefully according to the light of truth, and to God's plan for these things in life.

Proper assigning takes a lot of work, study, reading of Holy Scripture, Church teaching, prayer, proper reception to [good] spiritual direction, frequent use of the Sacraments.  And endlesss "beginning agains". 

And we know that our intellect can be 'co-opted" often (subtly and quietly) by our appetites and our emotions.    These lesser faculties can begin to "take over the shop" and call the shots. 

We can thus "assign" too much value to some things, and not enough value to other things.    Food, entertainment, mere sense matters, etc can begin to dominate.

We can give in to pressures of vanity, for instance; we can let our intellect "assign too much value" to our reputation, opinions, preferences, our "cultural standing". 

And this leads to all manner of disorder in other areas of our life, priorities, motives, etc.