I think one of the most important guiding principles has been this:—that every moment of my waking hours has always been occupied by some train of inquiry. In far the largest number of instances the subject might be simple or even trivial, but still work of inquiry, of some kind or other, was always going on.
The difficulty consisted in adapting the work to the state of the body. The necessary training was difficult. Whenever at night I found myself sleepless, and wished to sleep, I took a subject for examination that required little mental effort, and which also had little influence on worldly affairs by its success or failure.
On the other hand, when I wanted to concentrate my whole mind upon an important subject, I studied during the day all the minor accessories, and after two o’clock in the morning I found that repose which the nuisances of the London streets only allow from that hour until six in the morning.
At first I had many a sleepless night before I could thus train myself.
I believe my early perception of the immense power of signs in aiding the reasoning faculty contributed much to {486} whatever success I may have had. Probably a still more important element was the intimate conviction I possessed that the highest object a reasonable being could pursue was to endeavour to discover those laws of mind by which man’s intellect passes from the known to the discovery of the unknown.
This feeling was ever present to my own mind, and I endeavoured to trace its principle in the minds of all around me, as well as in the works of my predecessors.
APPENDIX.
MIRACLES. Note (A), page [394].
IT has always occurred to my mind that many difficulties touching Miracles might be reconciled, if men would only take the trouble to agree upon the nature of the phenomenon which they call “Miracle.” That writers do not always mean the same thing when treating of miracles is perfectly clear; because what may appear a miracle to the unlearned is to the better instructed only an effect produced by some unknown law hitherto unobserved. So that the idea of miracle is in some respect dependent upon the opinion of man. Much of this confusion has arisen from the definition of Miracle given in Hume’s celebrated Essay, namely, that it is the “violation of a law of nature.”