This is a photographic reprint of the original, which insures faithfulness to the original. The Dark Night, though only a short treatise in comparison with the remaining works of St. John of the Cross, is perhaps from a practical point of view the most important of the whole senes. Instructions for beginners may be found in abundance; even the Night of the sense, as St. John informs us, has had numerous exponents; but in the Night of the spirit he breaks fresh ground. If it is one of God's ordinances that all spiritual life must be regulated by a director so that pitfalls may be avoided, a soul plunged into the Night of the spirit depends more than any other upon the intelligent guidance of an experienced director, partly on account of its natural reluctance to proceed along a path beset with so many difficulties, partly because the very fact of its being in darkness prevents it from seeing clearly with its own eyes. In the Ascent and the Dark Night St. John has traced the way with admirable lucidity and simplicity, but these books, especially the latter, are chiefly addressed to the director. I t is impossible to read them without gaining the conviction that his is the absolutely safe way; there may be others, less straight, less rugged, but neither so safe nor so direct. St. John, taking his position on the firm basis of the psychology and theology of St. Thomas Aquinas, and guiding himself by the light of Holy Scripture, pitilessly dissects the soul and its operations, separating not only what is dangerous or unsound, but everything that is not directly conducive to his ultimate aim, the union of the human will with the holy will of God. A work of this magnitude must be begun by God, and accomplished by Him. The beginning consists in the grace of vocation, the end in the Beatific Vision. Between these two there lies a vast distance which it takes a lifetime to cover, where the generous and intelligent co-operation of the soul is indispensable. This is partly active, and consists in the systematic denial of everything that could give satisfaction to body or soul, as explained in the Ascent; and partly passive (as shown in the Dark Night), where the soul assists God's operation by submitting to His chastising hand, like a patient under the knife of the surgeon. The number of souls called to the contemplative life in its widest sense is even nowadays greater than is commonly supposed. They are not confined to Religions Orders, but are to be found in every station of life, and in every country, for 'the spirit breatheth where it will.' Many proceed no farther than the initial stages; few persevere as far as the spiritual night; while those who attain to perfection are but exceptions. 'l\Iany praise and bless Jesus as long as they receive some consolation from Him, but if He hide Himself and leave them for a little while, they fall either into complaining or into excessive dejection.' This general falling off may be partly attributed to a want of understanding and guidance which St. John in the book before us undertakes to remedy. It may be useful for some readers of St. John's works to find here a short sketch of the experiences a soul generally makes on its journey through the realms of mysticism. Let us suppose that it has been unexpectedly struck by a ray of divine grace. It may never really have been estranged from God since the day of baptism, or it may have strayed; no essential difference would result therefrom, because motion is determined not so much by the direction whence it proceeds but whither it tends.