Among the many virtues that constitute the structure of the spiritual edifice, Saint Anthony emphasises, as a true Franciscan, four that reveal his spirituality: humility, obedience, poverty and charity.

As the basis for his mystical exaltation, the Saint places humility, root and mother of all virtues. Humility became his identity, the essence of his way of thinking and acting, as it clear from his Sermones.

This is the consequence of reflection on the abjection and nothingness in human nature.

Considering the physiological consequences of the nutrition and digestion of the human body which is required to defecate, Saint Anthony says that, faced with a similar lowliness, every man should be deeply humiliated. Even conception and birth are, for Anthony, reasons to rid oneself of any feelings of arrogance.

Humility helps man to know himself and God. As fire reduces things to ashes and lowers things that are tall, so does humility force the arrogant to bend down and humble himself, repeating the words of Genesis, "Ashes to ashes, dust to dust." (3,19) The truly humble considers himself a worm, a son of worms and putridity. Scorn for oneself (contemptus sui) is the main virtue of the just man, with which he, earthworm, contracts and lengthens himself to reach heavenly goods. Arrogance is the worst sin before God and humility is the most noble of virtues. It sustains with modesty ignoble and dishonest things and is helped by divine grace.

Humility is compared to a flower, since, like a flower, it has the beauty of colour, the gentleness of perfume and the hope of fruit. "When I see a flower," observes Saint Anthony, "I hope for fruit; in the same way, when I see a humble man, I hope for his heavenly beatitude."

The saint places the seat of the virtue of humility in the heart. As the heart regulates the life of the body, in the same way humility presides over the life of the soul. As the heart is the first organ to live and the last to cease to exist, in the same way the virtue of humility dies with it. If the cardiac muscle can bear neither pain nor serious disease without compromising the life of the other organs, the virtue of humility can neither complain of the offences received nor torment itself about other people's well-being, because if humility is not up to its duties, the edifice of the other virtues will collapse.

Brother Anthony distinguishes ten levels of humility which synthesise the whole path to perfection.

1. Humility requires man to keep in mind the humble origins of his body,
2. his gestation in his mother's womb,
3. his unadorned birth,
4. his difficult earthly pilgrimage,
5. his weaknesses,
6. and he should always keep in mind the thought of death, "bitterer than any bitterness."
7. Humility, in addition, urges man to participate in the mystery of the humble Christ,
8. who became his servant and redeemer,
9. testimony to love pushed to the brink of folly.
10. The advancement of man along the path to perfection is in proportion to his lowering, since every man who rises up shall be lowered and he who humbles himself shall be uplifted.

Through these ten levels he, conscience of his infirmity and his poverty, enters into spiritual life thanks to God's grace, he frees himself from the dangerous things that weigh him down, he contemplates more clearly his authentic nature as a person and he discovers the presence of God in the intimate depths of his soul. Humility moves the saint because it lowers, so that it may then rise higher and God can grow in him.

No page of the Sermones is unfaithful, not to a principle of vainglory which would be incompatible with sainthood, but not even in a way that would reveal the knowledge of its real value, which could even go together with humility. The desire to make himself "small" was alive in Anthony. He wished to keep his merits hidden and his defects visible, to guard against any attack from arrogance.

"You, who are ashes and dust, what do you take pride in? The sanctity of life? But it is the spirit that sanctifies; not yours, that of God. Do you enjoy the praise you receive for your discourse? But it the Lord who bestows the gift of eloquence and knowledge. What is your tongue, if not a pen in the hand of a scribe?" "If an adulator tells you, 'You are an expert and you know many things,' it is as if he were telling you, 'you are demoniacal' (the Greek use the word daimonion to describe one who knows a great many things). You must respond to them with Christ, 'I am not demoniacal,' because I know nothing of myself and there is nothing good in me. I glorify my God, I attribute everything to him and I render him glorious. He is the prince of every knowledge and every science."

Naturally, man co-operates with divine bounty. It is impossible not to be aware of this. Nonetheless, the saint proceeds with caution in evaluating his personal merits. He underestimates them rather than exaggerating their importance. Above all, he never divides the positive aspects of life from the negative ones. The virtuous man "together with the good things he does, retains his defects for his humiliation. And not knowing how to overcome them, despite their insignificance, is a continual admonition to live in humility."

The patrimony of virtue, that Brother Anthony worked continually to increase, was united with a great knowledge. The Sermones are a splendid demonstration of Brother Anthony of Padua's excellent cultural level.

The following special qualities, though perhaps not the rare qualities of a genius, emerge from his writings:

• a speculative mind,
• a powerful memory,
• a busy imagination,
• a sharp capacity for observation,
• a delicate sensibility,
• and an indomitable will to learn. The first biography of Saint Anthony points out this singular prerogative of the young Franciscan from Padua.

The saint did not consider himself to be, nor did he act like, an erudite. On the contrary, he professed to be a follower of the most illustrious teachers. Brother Anthony compared himself to Ruth, the gleaner, in the field of learning. He followed behind the "great" trying to gather the crumbs of their teachings.

Speaking of his science, at the beginning of the Sermones, and aware of its unimportance, he defines it in a short phrase in which each word is an act of humility: a trickle of poor little science. This was not just something he said when faced with this serious assignment which he undertook with fear and a sense of discretion, because upon completing the work he felt like the most insignificant of all the monks.

He invites his fellow brothers who read his work to give any praise or honours to Christ for anything edifying he had written an to attribute to his own ignorance any defects found in the work. He entrusted the elders of the Order with the job of reviewing and correcting his pages.