long as the minds of men are directed to the perfecting of ship-building. In like manner, the various facts in the educational processes of Nature, in so far as they have been correctly ascertained in the previous part of this Treatise, must form the unalterable basis for every future improvement in education. These facts, or principles, will very probably be found to form only a part of her operations;--but as they do really form _a part_, they will become a nucleus, round which all the remaining principles when discovered will necessarily congregate. We shall here therefore endeavour very shortly to recapitulate the several principles or laws employed by Nature in her academy, so far as we have been able to detect them; as it must be upon these that not only we, but all our successors in the improvement of education, must hereafter proceed. We have seen in a former chapter, that the educational processes of Nature divide themselves distinctly into four different kinds. _First_, the cultivation of the powers of the mind:--_Second_, the acquisition of knowledge:--_Third_, the uses or application of that knowledge to the daily varying circumstances of the pupil:--and _Fourth_, the ability to communicate this knowledge and experience to others. The _first_ department of Nature's teaching, that of cultivating the powers of her pupil's mind, we found to depend chiefly, if not entirely, upon one simple mental operation, that of "reiterating ideas;" and from numerous examples and experiments it has been shewn, that wherever this act of the mind takes place, there is, and there must be, mental culture; while, on the contrary, wherever it does not take place, there is not, so far as we can yet perceive, the slightest indication that the mind has either been exercised or benefited.