While taking a look at how fear is involved in our human lives, Saint Thomas analyses the different types of fear, upholding Saint John Damascene and Saint Gregory of Nyssa’s texts on the subject. We’re all familar in some way with the things mentioned below, though perhaps not with an understanding of them as types of fear of something. Food for thought! 

“I answer that, as stated above.., fear regards a future evil which surpasses the power of him that fears, so that it is irresistible. Now man's evil, like his good, may be considered either in his action or in external things. In his action he has a twofold evil to fear.

Laziness
First, there is the toil that burdens his nature: and hence arises ‘laziness,’ as when a man shrinks from work for fear of too much toil.

Shame
Secondly, there is the disgrace which damages him in the opinion of others. And thus, if disgrace is feared in a deed that is yet to be done, there is ‘shamefacedness’; if, however, it be a deed already done, there is ‘shame.’

On the other hand, the evil that consists in external things may surpass man's faculty of resistance in three ways.

Amazement
First by reason of its magnitude; when, that is to say, a man considers some great evil the outcome of which he is unable to gauge: and then there is ‘amazement.’

Stupor
Secondly, by reason of its being unwonted; because, to wit, some unwonted evil arises before us, and on that account is great in our estimation: and then there is ‘stupor,’ which is caused by the representation of something unwonted.

Anxiety
Thirdly, by reason of its being unforeseen: thus future misfortunes are feared, and fear of this kind is called ‘anxiety.’ ”

(Extracts from the Summa Theologica, part II, question 41)