Even the foot-notes to a work may have to be disregarded, in the first instance.  They may act like a second author, and keep up an irritating friction.  There is, doubtless, a consummate power of annotation that anticipates difficulties, and clears away haze, without distracting the mind.  There is also an art of bringing out relief by an accompaniment, like the two images of the stereoscope.  This is most likely to arise through a living teacher or commentator, who, by his tones and emphasis, as well as by his very guarded and reserved additions, can make the meaning of the author take shape and fulness.

As the chief text-book is chosen, among other reasons, for its method and system, any defects on this head may be very suitably supplied, during the reader’s progress, by notes or otherwise.  When the end is clearly kept in view, we shall not go wrong as to the means:  the spirit will remedy an undue bias to the letter.

The subjects that depend for their full comprehension upon a certain method and order of details, are numerous, and include the most important branches of human culture.  The Sciences, in mass, are avowedly of this character:  even such departments as Theology, Ethics, Rhetoric, and Criticism have their definite form; and, until the mind of the student is fully impressed with this, all the particulars are vague and chaotic, and comparatively useless for practical application.  So, any subject cast in a polemic form must be received and held in the connection thereby given to it.  If the arguments pro and con fall out of their places in the mind of the reader, their force is missed or misconceived.

History is pre-eminently a subject for method, and, therefore, involves some such plan as is here recommended.  Every narrative read otherwise than for mere amusement, as we read a novel, should leave in the mind—­(1) the Chronological sequence (more or less detailed); and (2) the Causal sequence, that is, the influences at work in bringing about the events.  These are best gained by application to a single work in the first place; other works being resorted to in due time.

Of the non-methodical subjects, forming an illustrative contrast, mention may be made of purely didactic treatises, where the precepts are each valuable for itself, and by itself:  such as, until very recently, the works on Agriculture, and even on Medicine.  A book of Domestic Receipts, consulted by index, is not a work for study.

Poems and fictitious narrations will naturally be regarded as of the un-methodical class.  If there are exceptions, they consist of long poems—­Epics and Dramas—­whose plan is highly artistic, and must be felt in order to the full effect.  Probably, however, this is the merit that the generality of readers are content to miss, especially if greater strain of attention is needed to discover it.  Readers bent on enjoyment dwell on the passing page, and are not inclined to carry with them what has gone before, in order to understand what is to follow.