Objection 1. It would seem that daring is not contrary to fear. For Augustine says (QQ. 83, qu. 31) that "daring is a vice." Now vice is contrary to virtue. Since, therefore, fear is not a virtue but a passion, it seems that daring is not contrary to fear.
Objection 2. Further, to one thing there is one contrary. But hope is contrary to fear. Therefore daring is not contrary to fear.
Objection 3. Further, every passion excludes its opposite. But fear excludes safety; for Augustine says (Confess. ii, 6) that "fear takes forethought for safety." Therefore safety is contrary to fear. Therefore daring is not contrary to fear.
On the contrary, The Philosopher says (Rhet. ii, 5) that "daring is contrary to fear."
I answer that, It is of the essence of contraries to be "farthest removed from one another," as stated in Metaph. x, 4. Now that which is farthest removed from fear, is daring: since fear turns away from the future hurt, on account of its victory over him that fears it; whereas daring turns on threatened danger because of its own victory over that same danger. Consequently it is evident that daring is contrary to fear.
Reply to Objection 1. Anger, daring and all the names of the passions can be taken in two ways. First, as denoting absolutely movements of the sensitive appetite in respect of some object, good or bad: and thus they are names of passions. Secondly, as denoting besides this movement, a straying from the order of reason: and thus they are names of vices. It is in this sense that Augustine speaks of daring: but we are speaking of it in the first sense.
Reply to Objection 2. To one thing, in the same respect, there are not several contraries; but in different respects nothing prevents one thing having several contraries. Accordingly it has been said above (23, 2; 40, 4) that the irascible passions admit of a twofold contrariety: one, according to the opposition of good and evil, and thus fear is contrary to hope: the other, according to the opposition of approach and withdrawal, and thus daring is contrary to fear, and despair contrary to hope.
Reply to Objection 3. Safety does not denote something contrary to fear, but merely the exclusion of fear: for he is said to be safe, who fears not. Wherefore safety is opposed to fear, as a privation: while daring is opposed thereto as a contrary. And as contrariety implies privation, so daring implies safety.
Source: Summa Theologica (New Advent)