We must now consider the vices opposed to prudence.
For Augustine says (Contra Julian. iv, 3): "There are vices opposed to every virtue, not only vices that are in manifest opposition to virtue, as temerity is opposed to prudence, but also vices which have a kind of kinship and not a true but a spurious likeness to virtue; thus in opposition to prudence we have craftiness."
Accordingly we must consider first of all those vices which are in evident opposition to prudence, those namely which are due to a defect either of prudence or of those things which are requisite for prudence, and secondly those vices which have a false resemblance to prudence, those namely which are due to abuse of the things required for prudence.
And since solicitude pertains to prudence, the first of these considerations will be twofold: (1) Of imprudence; (2) Of negligence which is opposed to solicitude.
Under the first head there are six points of inquiry:
A Concerning imprudence, whether it is a sin?
A Whether it is a special sin?
A Of precipitation or temerity;
A Of thoughtlessness;
A Of inconstancy;
A Concerning the origin of these vices.