Page:History of botany (Sachs; Garnsey).djvu/14

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The Author's Preface.

influence on posterity, of works written three hundred or even one hundred years ago.

But it is a very different matter when the author of a book like mine ventures, as I have done for sufficient reasons but at the same time with regret, to sit in judgment on the works of men of research and experts, who belong to our own time and who exert a lively influence on their generation. In this case the author can no longer appeal to the consentient opinion of his contemporaries; he finds them divided into parties, and involuntarily belongs to a party himself. But it is a still more weighty consideration that he may subsequently change his own point of view, and may arrive at a more profound insight into the value of the works which he has criticised; continued study and maturer years may teach him that he overestimated some things fifteen or twenty years ago and perhaps undervalued others, and facts, once assumed to be well established, may now be acknowledged to be incorrect.

Thus it has happened in my own case also in some but not in many instances, in which I have had to express an opinion respecting the character of works which appeared after 1860, and which to some extent influenced my judgment on the years immediately preceding them. But this was from fifteen to eighteen years ago when I was working at my History. It might perhaps be expected that I should remove all such expressions of opinion from the work before it is translated. In some few cases, in which this could be effected by simply drawing the pen through a few lines, I have so done; but it appeared to me that to alter with anxious care every sentence which I should put into a different form at the present day would serve no good