Blasphemy and Blindness of The Mind

Following unbelief, there are two more vices which work against faith: blasphemy which is to deny God what is due to Him and to attribute to Him what should not be; blindness of the mind, on the other hand, is the impediment of intellectual vision, and it can be either a punishment or a sin.


In the previous lesson we saw that, according to the exposition found in the Theological Sum of St. Thomas, the first vice contrary to faith is unbelief. We have also seen how unbelief is tripartite: unbelief in general, heresy and apostasy, and we have analysed all their aspects.

St. Thomas states that there are two more kinds of vices against the faith, they are:

a- Blasphemy

b- Blindness of the mind (and the dullness of the senses)

Blasphemy is a vice contrary, not to the act of faith, like unbelief, but to the confession of faith and we recalled how important the confession of faith is for faith itself. Blindness of the mind and dullness of the senses are instead a vice contrary to the gift of the intellect. The gift of the intellect is one of the seven gifts of the Holy Spirit which, together with science, go to perfect the virtue of faith.

- What is the gift of the intellect?
It is that particular gift of the Holy Spirit which allows sharpness, a penetration in grasping the truths of the faith and the implications of the truth of the faith, therefore we speak of the intellect being raised by the virtue of faith.


St Thomas dedicates two questions to blasphemy: numbers thirteen and fourteen. For now we focus on question thirteen, which deals with blasphemy in general. In the first article, St. Thomas defines blasphemy as denying "of Him what does befit Him" and attributing to God "what is not befit Him". The matter of blasphemy is therefore the denial of a perfection of God or the attribution to Him of something that does not belong to Him or is not appropriate to Him. This happens in two ways:

- Through the intellect. That is when we think and say things about God that do not befit Him. For example, that God is bad or unjust or we attribute to Him aspects or adjectives that are not fitting and are not appropriate to His Holiness.

- By the affective order. It happens when it is not just a question of reasoning or an expression, but there is also an internal charge that St. Thomas defines as "an affective rejection".
The "perfect" blasphemy is when these two levels come together, the intellectual order and the affective order.

It is interesting to note how blasphemy, belonging to the category of unbelief, is for St. Thomas an extremely grave sin, a mortal sin. Unlike ourselves, who have a strange idea of mercy, as if it were an excuse for our actions, the people of the medieval period and in this case St. Thomas were more truthful. Still, when St Thomas treats the gravity of the sin of blasphemy he points out, that it is true that the conditions of the subject can transform the sin from grave to venial, he says:

There are two ways in which blasphemy can sneak up on someone unawares without deliberation: In one way, when he does not advert to the fact that what he is saying is blasphemous. This can happen when, because of some passion, someone erupts suddenly into words which are suggested by his imagination and whose meaning he is not thinking about.”

The most striking case: one blasphemes in a foreign language that they do not know, or they say it in their own language, but do not realise that it is a blasphemy because of their ignorance. For example, children who repeat what they hear without realising what it means. Instead,

“When he adverts to the fact that this is blasphemy, taking into consideration the meaning of the words. And in such a case he is not excused from mortal sin, just as one is not excused from mortal sin if, because of a sudden movement of anger, he kills someone seated next to him.

Therefore, if one knows the meaning of what they choose to say or think (this does not refer to the temptations of blasphemy), the fact that certain words are expressed because they are driven by impetus, does not excuse the person from sin, because anger is a passion that must be curbed. If someone blasphemes out of anger, they cannot think that it doesn’t matter, they must confess the sin so that grace can take possession of their soul again.


a- What does blindness of the mind imply?
It is the impediment of intellectual vision. Not of the natural intellect, but of that elevated vision, which is given by the light of the theological virtue of faith. Blindness means blindness, not being able to see anymore.

b- What does the dullness of the senses imply?
A debilitation, a weakening of the higher senses with respect to spiritual goods. A sort of weakness not of the will, but of the intellect, a sort of weakening of the eyes that see out of focus and no longer distinguish from a spiritual point of view.

Why is blindness of the mind a sin?
It’s a sin because the person decides not to be informed of the knowledge they should know, that is the truths of the faith, and so is guilty of their own ignorance; or they prefer to turn to something else that is more delightful to them, but which is less important. Blindness, therefore, is either a punishment or a sin; in the first case it will be the consequence of very specific sins, in the second it is a sin itself.

The dullness of the senses. It is a weakness; St. Thomas defines it as a "a certain weakness of mind with respect to the consideration of spiritual goods": lack of acuity, lack of readiness to grasp, lack of a certain lucidity of knowledge.
St. Thomas, in the third article of question 15, recalls a principle in Aristotle's Nicomachean Ethics:

“Each individual does those things best that he takes pleasure in, whereas the contrary things he does feebly or not at all.”

Recalling this principle, St. Thomas affirms that precisely because one does what one is inclined towards more easily, what pleases them and gives them satisfaction and is much less so towards what causes them displeasure, they come to grasp a fundamental point. Two deadly sins, linked above all to the flesh, namely gluttony and lust, are at the origin of blindness and dullness, because they bend and incline the person towards the flesh, towards pleasures of the senses. In this way humans find themselves more ready to be devoted to these pleasures than to spiritual research, and thus they weaken and enfeeble the intellect to the point of making it blind.

Lust, being the strongest and most violent passion with respect to gluttony, is what causes blindness; the throat, being less strong, causes dullness of the senses.

St. Thomas thus recalls the biblical passage present in the first chapter of the prophet Daniel. Daniel, together with the three young men Ananias, Azaria and Misaele, is captured and taken to Babylon to be trained with the other youth at the King's court to become one of his various officials. They are therefore given a specific diet, but Daniel refuses to eat because they are forbidden foods for the Jews and proposes to one of the superintendents, who was their teacher, that they eat only legumes. This type of nutrition, as well as the purity of these young people, ensures they become wise, so much so that Daniel acquires the gift of prophecy and the interpretation of dreams. St. Thomas explains that the gifts received by Daniel also came from the fact that he had been able to tame the double passion of the flesh: gluttony and lust.

This perspective is very interesting because it puts us in a dimension very far from that acquired in modern age and reminds us of the unity between body and spirit: if the passions of the flesh, even if they are not the most serious, are not tamed, they can block the intellect and the light of faith and can lead to the terrible consequence of the blindness of the intellect and the blindness of the senses.

From today's lesson it’s clear the importance of preserving, cultivating, defending the immense gift of faith and doing it from all aspects: clarification, strengthening and purification of the intellect, but also purification and strengthening of the will. Knowing that the principle of faith is always by the grace of God for which prayer is fundamental.

Dona Ora