MENTAL prayer is called by St. Gregory Nazianzen a conference, or conversation with God. St. John Chrysostom speaks of prayer as a discourse with the divine majesty. According to St. Augustine it is the raising up of the soul to God. St. Francis de Sales de scribes it as a conversation of the soul with God, by which we aspire to Him and breathe in Him, and He, in return, inspires us and breathes on us.
Father Bertrand Wilberforce, in his tract on “Mental Prayer,” writes:
All prayer is the speaking of the soul to God. This may be done in three ways. For the prayer may be either in thought only, unexpressed in any external way, or on the other hand the secret thoughts and feelings of the soul may be clothed in words; and these words, again, may either be confined to a set form, or they may be words of our own, unfettered by any form, and expressing the emotions of our soul at the moment. In the first case our prayer will be purely mental; in the second, in which we employ a set form of words, it will be vocal prayer; in the third case, where the prayer is chiefly in thought, but these thoughts are allowed to break forth into words in any way that at the moment seem best to express the feelings of the soul, it is a mixture of mental and vocal prayer, but as the words are spontaneous and not in any prescribed form, it may justly be considered as mental prayer.
In an audience with the Pope, we might read a written address to his Holiness, or we might trust to the words that might occur at the moment, to express what we desired to convey to his mind. But if God were to enable the Pope to read the thoughts of our mind, we might then simply stand silent in his presence, and he would see all that we wanted to express. The formal address would be vocal prayer, the silent standing before his throne would be purely mental prayer, the conversation with unprepared words would be a mixture of the two, and might be called mental prayer in a more general and extended sense. God knows our secret thoughts more clearly than we can express them, more certainly than we ourselves can know them, and words therefore are not necessary in our intercourse with Him, though often a considerable help to us.
A set form of words spoken, or read, can not be called prayer at all, unless the mind intends it as prayer, and gives some kind of spiritual attention, either to the actual sense of the words themselves, or to God Himself while they are being uttered. Shakespeare spoke as a theologian when, in Hamlet, he put into the mouth of the king, who asked for pardon without repentance:
My words go up, my thoughts remain below,
Words without thoughts never to heaven go.
God condemned the merely material homage of the Jews by declaring, "This people honoreth Me with their lips, but their heart is far from Me." All prayer, therefore, of whatever kind, must be "in spirit and in truth" (John iv. 23), but vocal prayer is confined to a prescribed form of words, whereas mental prayer is the spontaneous utterance of the soul either with or without words. When St. Francis said an Our Father, or recited his office, he used vocal prayer; when he knelt before God without a word his prayer was purely mental; when he spent the whole night in saying "My God and my all," his mental prayer was mingled with words which expressed the burning love of his seraphic soul.
St. Alphonsus says, "He who neglects meditation (a part of mental prayer), and is distracted by the affairs of the world, will not know his spiritual wants, the dangers to which his salvation is exposed, the means he ought to take to conquer temptations, and will forget the necessity of the prayer of petition for all men; thus he will not ask for what is necessary, and by not asking God s grace, he will certainly lose his soul."
In the same way St. Teresa asks: "How can charity last, unless God gives perseverance? How will the Lord gives us perseverance if we neglect to ask Him for it? And how shall we ask it without mental prayer? With out mental prayer there is not the communication with God, which is necessary for the preservation of virtue." The holy Doctors agree that those who persevere in mental prayer will live in God’s grace. The following words are the deliberate sentence of the holy Doctor St. Alphonsus, the conclusion gathered from his vast learning and experience: "Many say the Rosary, the Office of Our Lady, and perform other acts of devotion, but they still continue in sin. But it is impossible for him who perseveres in mental prayer to continue in sin; he will either give up mental prayer, or renounce sin. Mental prayer and sin can not exist together. And this we see by experience; they who make mental prayer, rarely fall into mortal sin; and should they have the misery of falling into sin, by persevering in mental prayer, they see their misery, and return to God. Let a soul, says St. Teresa, be ever so negligent, if she perseveres in mental prayer, the Lord will bring her back to the haven of salvation."
If this were merely the opinion of St. Alphonsus himself it would be of immense weight, considering his resplendent sanctity, his vast spiritual learning, and the varied experience of his long and active life, but besides this the holy Doctor is here only summing up, in one sentence, the teaching and experience of all the doctors, saints, writers, preachers, and confessors of the whole Church since the beginning. What stronger argument could be used to prove the importance and necessity of mental prayer?