ESSAYS 315 



duced in the mind of a beginner by the manner in which the elements of science 

 are taught and have necessarily to be taught. The teacher has to point out that 

 the conclusions of science rest on experience, and not on authority ; yet he will be 

 unable to do more than give illustrations of the physical truths he tea.ches. He 

 must explain theories before the evidence in their support can be fully understood 

 by the pupil ; he must formulate laws before he can discuss all that is implied in 

 them. He must, in fact, frequently appeal to authority ; but it is not the authority 

 of the old scholastic tradition relying on the wisdom of one man strengthened by 

 imitative echoes of a number of mediocrities. It is the authority of independent 

 intellects who have spent a lifetime in testing their conclusions. For every man 

 who tries to establish a law there will be a number of others eager to find flaws, 

 and the verdict of the time is the combined result of a concourse of opposing 

 tendencies. The difference is the same as that between the judgment of an 

 autocratic ruler who knows no law but that of his own will, and the pronounce- 

 ment of a judge who, having heard both sides, decides according to the evidence 

 that has been put before him. 



Science, like all other branches of knowledge, has its dogmas, but they are 

 admitted to be temporary only. Though they are based on experience, fresh 

 evidence may qualify or alter our interpretation of that experience. Such altera- 

 tions mark an advance, but do not shake the structure ; a scientific revolution is a 

 constitutional progress, and not the violent upheaval of a fundamental faith. The 

 atomic theory remains true in spite of the discovery that atoms may be split up, 

 just as a house built of bricks will remain a house built of bricks, though each 

 brick itself is made up of molecules. All I have said on this subject is only a 

 collection of truisms to the trained man of science. He knows that the interpre- 

 tation of the facts is subject to change ; but to the beginner theories must often 

 appear to be immovable dogmas, and in the early stages the teacher cannot help 

 being dogmatic. Nevertheless, there may be room for improvement. Students 

 are often shown how to compress a volume of air, and to find the relation between 

 the pressure and the compression. I am afraid they are then sometimes led to 

 believe that they have proved Boyle's law. They have done nothing of the kind ; 

 for they have only performed one or two experiments, the results of which are not 

 inconsistent with the law. The experiments dealt with only one gas, and the 

 measurements did not possess any high degree of accuracy. A proof is, indeed, 

 impossible, because the law is not strictly true. The same remarks apply to the 

 experiments often found described in elementary books on laboratory work, in 

 which Ohm's law is said to be proved when it has only been illustrated. Teachers 

 ought to be careful to put such experiments in their proper light, because a wrong 

 impression in the early stages of scientific instruction may lead to that kind of 

 arrogance which belongs to the intelligent youngster in any subject, but is, per- 

 haps with some justification, laid more particularly to the charge of the half- 

 fledged learner of science. I have had a sufficiently long experience as a teacher 

 of elementary science to speak out frankly on the subject, because I know its 

 great difficulties. It is well that these should be clearly understood. 



At the present time we are urging the importance of extending the scientific 

 instruction which is being given in schools. Some base the claims of science on 

 its utilitarian value ; but if this were the main object, the teaching should be princi- 

 pally addressed to those who will ultimately require a knowledge of science in 

 their profession. If we adopt this view, the teaching would be simple enough. 

 The future student of science is drawn to his subject by an instinctive feeling of 

 predilection, properly classified by Karl Pearson as an aes'.hetic feeling ; this 



