as if they were falling steadily into a bottomless abyss, between black and slippery rocks. In this book there is no common light or air; as a spiritual abode it will be insupportable to those who come unprepared. Do not enter here from literary curiosity; there are hardly any dainty nick-nacks, and the botanist in search of fine images will find as few flowers here as on the polar ice-banks. I tell them that this is a boundless desert, where they will die of thirst. They will find here very few phrases which one may handle and admire after the way of literary critics; nothing but jets of flame or blocks of ice. Do not seek for roses in Iceland. Some flower may still linger between two icebergs--and indeed there are strange outbursts, unknown expressions, unheard-of analogies, but they will not repay you for the time lost in coming so far to pluck them. Before entering here one must be in a philosophic state as different from our ordinary condition as the state of waking is from that of slumber. Porphyry, in his _Principles of the Theory of Intelligibles_, seems to me to have written a warning which might fitly stand at the beginning of this book--“By our intelligence we say many things of the principle which is higher than the intelligence. But these things are divined much better by an absence of thought than by thought. It is the same with this idea as with that of sleep, of which we speak up to a certain point in our waking state, but the knowledge and perception of which we can gain only by sleeping. Like is known only by like, and the condition of all knowledge is that the subject should become like to the object.”