overestimate the importance of one's own labors.
Yet even an effort such as this may suffice to give public opinion a true or a false direction. Great results are sometimes determined by humble agencies. "A ridge-tile of a cottage in Derbyshire," says Gisborne, "decides whether the rain which falls from heaven shall be directed to the German Ocean or the Atlantic."
Let the reader, before he enters on the inquiry whether ultramundane interference be a great reality or a portentous delusion, permit me one additional remark. He will find that, in treating that hypothesis, I have left many things obscure and uninterpreted. Where no theory was clearly indicated, I preferred to state the facts and waive all explanation, having reached that period of life when, if good use has been made of past years, one is not ashamed to say, "I do not know," in any case in which that is the simple truth. We do well, however, to bear in mind that a difficulty unsolved does not amount to an argument in opposition.*
To the many friends whose kindness has aided my undertaking, these pages owe their chief value. To some therein named I am enabled here to tender my grateful acknowledgments. To others who have assisted in private I am not less deeply indebted.
I doubt not that if I were to delay the publication of this book for some years I should find much to modify, something to retract. But if, in this world, we postpone our work till we deem it perfect, death comes upon us in our hesitation, and we effect nothing, from bootless anxiety to effect too much. R. D. O.
"Where we cannot answer all objections, we are bound, in reason and in candor, to adopt the hypothesis which labors under the least."—" Elements of Logic," by Archbishop Whateley.