Concerning the Ten Commandments, which are the Heads of the Law (143-145)

But what is it that I am saying? The appearance and idea of a present good, or of one that is accounted such, rouses up and excites the soul which was previously in a state of tranquillity, and raises it to a high degree of elation, like a light suddenly flashing before the eyes; and this passion of the soul is called pleasure.

But the contrary to good is evil, which, when it forces its way in, and inflicts a mortal wound, immediately fills the soul against its will with depression and despondency; and the name of the passion is sorrow.

But when the evil presses upon the soul, when it has not as yet taken up its habitation in it, but when it is only impending, being about to come and to agitate it, it sends before it agitation and suspense, as express messengers, to fill the soul with alarm; and this passion is denominated fear.