[12] For the methods of employing this exercise and the books best adapted for it, see Note I. CHAP. II. _On the Methods by which Nature may be imitated in the Pupil's Acquisition of Knowledge; with a Review of the Analogy between the Mental and Physical Appetites of the Young._ The second step in the progress of Nature's pupil is the acquisition of knowledge.--This has always been considered a chief object in every system of education; and the discovery of the most efficient means by which it may be accomplished, must be a matter of great importance. In our remarks upon this subject in a previous chapter, we have shewn, that Nature in her operations employs four distinct principles for accumulating knowledge, for retaining it upon the memory, and for keeping it in readiness for use at the command of the will. There are, _First_, the "reiteration of ideas" by the mind, without which there can be no knowledge; _Secondly_, the principle of "Individuation," by which the knowledge of objects and truths is acquired one by one; _Thirdly_, the principle of "Grouping," or Association, in which the mind views as one object, what is really composed of many; and, _Fourthly_, the principle of "Analysis," or Classification, in which the judgment is brought into exercise, the different portions of our knowledge are arranged and classified under different heads and branches, and the whole retained in order at the command of the will, when any portion of it is required.--Our object now is to consider, what means are within the reach of the parent and the teacher, by which Nature in these several processes may be successfully imitated, while they endeavour to communicate the elements of knowledge to the young. Ideas being the only proper food of the mind, Nature has created in the young an extraordinary appetite and desire for their possession. There is a striking analogy in this respect, between the strengthening of the body by food, and the invigorating of the mind by knowledge; and before proceeding to detail the methods by which the parent or the teacher may successfully break down and prepare the bread of knowledge for their pupils in imitation of Nature, it will be of advantage here to consider more particularly some of the circumstances connected with this instructive analogy. By tracing the likeness so conspicuously held out to us in this analogy by Nature herself, we shall be greatly assisted in evading the bewildering and mystifying influence of prejudice, and the reader will be much better prepared to judge of the value of those means recommended for nourishing and strengthening the mind by knowledge, when he finds them to correspond so exactly with similar principles employed by Nature for the nourishing and strengthening of the body by food. We shall by this means, we hope, be able to detect some of those fallacies which have long tended to trammel the exertions, and to prevent the success of the teacher in his interesting labours.