Contempt seems a very harsh word.
Contempt means : "disregard for something that should be taken into account."
Prologue
"In the name of the Father and the Son and of the Holy Ghost. I charge you and I beseech you with as such power and strength as the body of charity will permit, that whoever you may be who comes into possession of this book, whether as your own property or by borrowing,
that you neither read it nor write it or permit it to be read, written or spoken by any one who has not as far as you judge a full desire and intention to be a perfect follower of Christ not only in his active life but in the ultimate degree of contemplation to which it is possible to attain by grace in this life by a perfect soul still dwelling a mortal body; and you know that he does those things and has done so for a long time before, so that he has become capable of contemplative living by the virtuous means of active life, you may permit him to read this book.
Otherwise, it is not for him."
The author has charged us and beseeched us not to allow it to be read or discussed by anyone who has not "not only in his active life but in the ultimate degree of contemplation". Only those who have done so for a long time may read this book otherwise in the name of the Holy Trinity we are charged not to read it, discuss it or allow others to read it or to discuss it.
If you deny the the authority of the author when he invokes the name of the Holy Trinity charging you not to read or permit others to read, why should you take his authority serious when reading the rest?
The prayer of the prologue has no reference, but the next page (#53) restricts readership, discussion, and writing to a perfect soul, desiring to be a perfect follower of Jesus, capable of contemplative living.
For probably 20 years I've been struggling to imagine why Karl Rahner said "the Christian of the future will be a mystic or he will not exist." I felt I owed it to myself to try to understand mysticism. Besides, who on earth could satisfy those qualifications?
Those who have practice religious life are called to perfection and this book was very likely written for monks and not laity.
Mysticism is the idea that there exist things which we cannot see and the idea of attaining union with God through prayer. The attainment of lasting union with God is the goal of all Mystics.
If you deny that it is possible for anyone to live perfectly the active and contemplative life then you have forgotten about the Saints who have conquered themselves and become glorious by the grace Almighty God.
There are numerous approved texts for mysticism in the Catholic Church written by the Holy Ascetics and Godly Doctors and Sublime Mystics of God.
None of these did they charge in the name of the Father and of the Son and of the Holy Spirit not to read or permit to be read by the unworthy.
Rather, the Holy Saints of God have produced a massive mystical corpus where any of the uninstructed and unworthy may approach and find special grace.
For example Saint Melchtide's Book of Special Graces contains amazing mystical revelations which Jesus gave to her to help the faithful and religious alike.
The Life and Revelations of Saint Gertrude the Great contained innumerable mystical revelations, insights, prayers and visions and even the promise of Saint Gertrude as a powerful intercessor for all who seek God's grace.
The Spiritual Conferences of Saint John Cassian are a monastic instruction manual of ascetics, mysticism and praxis.
The Life and Letters of Saint Anthony the Great are examples of asceticism and mysticism and praxis as well.
These are but a few which I personally recommend.
Saints' Discussion Forums
Author
