There are some hundred Christian sects, every one of them acknowledging God and the Lord in its own way, without troubling themselves further about one another. In the study of nature, nay, in every study, things must of necessity come to the same pass. For what is the meaning of every one speaking of toleration, and trying to prevent others from thinking and expressing themselves after their own fashion? 523 To communicate knowledge by means of analogy appears to me a process equally useful and pleasant. The analogous case is not there to force itself on the attention or prove anything; it offers a comparison with some other case, but is not in union with it. Several analogous cases do not join to form a seried row: they are like good society, which always suggests more than it grants. 524 To err is to be as though truth did not exist. To lay bare the error to oneself and others is retrospective discovery. 525 With the growth of knowledge our ideas must from time to time be organised afresh. The change takes place usually in accordance with new maxims as they arise, but it always remains provisional. 526 When we find facts within our knowledge exhibited by some new method, or even, it may be, described in a foreign language, they receive a peculiar charm of novelty and wear a fresh air. 527 If two masters of the same art differ in their statement of it, in all likelihood the insoluble problem lies midway between them. 528 The orbits of certainties touch one another; but in the interstices there is room enough for error to go forth and prevail. 529 We more readily confess to errors, mistakes, and shortcomings in our conduct than in our thought. 530 And the reason of it is that the conscience is humble and even takes a pleasure in being ashamed. But the intellect is proud, and if forced to recant is driven to despair. 531 This also explains how it is that truths which have been recognised are at first tacitly admitted, and then gradually spread, so that the very thing which was obstinately denied appears at last as something quite natural. 532 Ignorant people raise questions which were answered by the wise thousands of years ago. 533 When a man sees a phenomenon before him, his thoughts often range beyond it; when he hears it only talked about, he has no thoughts at all. 534 Authority. Man cannot exist without it, and yet it brings in its train just as much of error as of truth. It perpetuates one by one things which should pass away one by one; it rejects that which should be preserved and allows it to pass away; and it is chiefly to blame for mankind's want of progress. 535 Authority--the fact, namely, that something has already happened or been said or decided, is of great value; but it is only a pedant who demands authority for everything. 536 An old foundation is worthy of all respect, but it must not take from us the right to build afresh wherever we will. 537