The preceding lines, rightly understood, express an entire system of philosophy.  It is mine.

I resume.

The domestic position at the commencement of our residence at Blackwater Park has been drawn with amazing accuracy, with profound mental insight, by the hand of Marian herself. (Pass me the intoxicating familiarity of mentioning this sublime creature by her Christian name.) Accurate knowledge of the contents of her journal—­to which I obtained access by clandestine means, unspeakably precious to me in the remembrance—­warns my eager pen from topics which this essentially exhaustive woman has already made her own.

The interests—­interests, breathless and immense!—­with which I am here concerned, begin with the deplorable calamity of Marian’s illness.

The situation at this period was emphatically a serious one.  Large sums of money, due at a certain time, were wanted by Percival (I say nothing of the modicum equally necessary to myself), and the one source to look to for supplying them was the fortune of his wife, of which not one farthing was at his disposal until her death.  Bad so far, and worse still farther on.  My lamented friend had private troubles of his own, into which the delicacy of my disinterested attachment to him forbade me from inquiring too curiously.  I knew nothing but that a woman, named Anne Catherick, was hidden in the neighbourhood, that she was in communication with Lady Glyde, and that the disclosure of a secret, which would be the certain ruin of Percival, might be the result.  He had told me himself that he was a lost man, unless his wife was silenced, and unless Anne Catherick was found.  If he was a lost man, what would become of our pecuniary interests?  Courageous as I am by nature, I absolutely trembled at the idea!

The whole force of my intelligence was now directed to the finding of Anne Catherick.  Our money affairs, important as they were, admitted of delay—­but the necessity of discovering the woman admitted of none.  I only knew her by description, as presenting an extraordinary personal resemblance to Lady Glyde.  The statement of this curious fact—­intended merely to assist me in identifying the person of whom we were in search—­when coupled with the additional information that Anne Catherick had escaped from a mad-house, started the first immense conception in my mind, which subsequently led to such amazing results.  That conception involved nothing less than the complete transformation of two separate identities.  Lady Glyde and Anne Catherick were to change names, places, and destinies, the one with the other—­the prodigious consequences contemplated by the change being the gain of thirty thousand pounds, and the eternal preservation of Sir Percival’s secret.