Picture Context: Dante and Beatrice speak to Piccarda and Constance of Sicily, in a fresco by Philipp Veit.

In OED, vehement, used as an adjective or adverb, is defined as intense or severe. This kind of intensity is due to pain, illness, heat, coldness or natural forces with great strength or violence. The usage in this sentence “The recent <em>vehement</em> earthquake happened in Sichuan, China, last week.” is an example.

The medium of carrying the intensity varies. It could be sound, actions, remedies (effects), debate, taste, personalities, thoughts, feelings, etc. I’m especially interested in this expression of feelings. Let’s see the ardent feelings in Dante.

Here, reader! Think,
If thou didst miss the sequel of my tale,
To know the rest how sorely thou wouldst crave;
And thou shalt see what vehement desire
Possess’d me, as soon as these had met my view,
To know their state. (Dante, Paradiso, Divina Commedia, Canto V)

This is what Dante tells us when Beatrice leads him into the second realm of Heaven and there are more than thousand splendors shining towards them, as if saying that their arrival is for multiplying their love. In short, Dante is very happy. He is no longer in control of himself as this intensity of desire occupies him and takes over the authority of allotting his feelings.

Let’s go back to the word, vehement. The etymology instructs us that the origin of the word comes from two parts. The prefix vehe- refers to “lacking”, and the tail mens means “mind”. The combination of these two parts becomes lacking mind. If we refer it to a person, we can say that his ardent desire which makes him act as he is out of his mind or beyond his mind which we might say he is full of imagination. As to the earthquake, we might infer that the severe quake exceeds the level of human perception. It is all about expectations. We have certain understanding of standards. When something happens beyond the standards, the vehement feeling aggregates.