fer the part of unconcerned spectators, which you now disdain, to publicly confess their belief or unbelief. What impels you to this, as I must call it, remarkable proceeding? The phenomena in question—so you answer—have been observed by scientific men of acknowledged eminence, whose credibility can not be questioned; these men have pronounced them real, therefore their reality is not to be doubted. Your acceptance is, in a word, based upon authority. Before I come to the point, permit me two general questions, which I must indeed answer myself, but which I still hope to answer in a way to which you can make no material objection. The first question is, What are the characterizing marks of a scientific authority? The second, What are the limits of the influence upon our own knowledge which we may grant to authority?
What are the characterizing marks of a scientific authority? You, of course, immediately admit that scientific authority is not a property which could be set down in the description of a person. You also agree with me that a person, who passes for authority in some particular science, can not transfer this quality at his pleasure to other provinces. The apocalyptic studies of Isaac Newton were not saved from quick forgetfulness by the authority of the discoverer of gravitation, and the high esteem which Ernst von Baer enjoys as a naturalist scarcely serves as a bill of protection for his Homeric investigations. It is quite true that scientific employment in itself, regardless of the object with which it is concerned, begets that purely theoretical interest in the truth which makes absolute truthfulness of statement in scientific questions a conscientious duty. I should believe, indeed, that only scientific occupation can produce absolute trustworthiness in theoretical questions, because it alone makes a correct estimate of such questions possible. That in this regard the authorities whom you name have, as well on account of their high scientific position as on account of their universally acknowledged personal character, a credibility above every doubt, is a matter of course. But the highest degree of credibility is not sufficient to make any man a scientific authority; there is requisite to this a special professional and in most cases indeed a technical training, which must have approved itself by superior accomplishments in the province concerned. He who has not acquired this professional and technical culture by long years of severe labor is neither capable of achieving anything himself nor of judging the works of others.
You will probably reply to me here that the authorities to whom you appeal are distinguished naturalists, and it is with natural phenomena that the present case has to do. Unhappily, however, I must gainsay you in this; I can not admit that we here have to do with natural phenomena, to whose critical examination naturalists as such, whatever department of natural science they may have been engaged in, are in any way competent. I go still further, indeed, and maintain
