TBANSACTI05S OF SECTION A. 553 



better get more fully settled iu his recent University chair before eToking the storm 

 of academic controversy which the ahaodoDmeut of the Ptolemaic system would 

 arouse. The same thing literally is going on to-day. I know of men who hesitate 

 to avow interest in these new investigations (I do not mean credence — the time is 

 too earlj' for avowing credence in any but the most rudimentary and definitely 

 ascertained facts — but hesitate to avow interest) until they have settled dowu 

 more securely and made a name for themselves in other lines. Caution and slow 

 progress are extremely necessary ; fear of avowing interest or of examining into 

 unorthodox facts is, I venture to say, not in accordance with the highest traditions 

 of the scientific attitude. 



We are, I suppose, to some extent afraid of each other, but we are still more 

 afraid of ourselves. We have great respect for the opinions of our elders and 

 superiors; we hud the matter distasteful to them, so we are silent. We have, 

 moreover, a righteous mistrust of our own powers and knowledge ; we perceive 

 that it is a wide region extending into several already cultivated branches of 

 science, that a many-sided and highly-trained mind is necessary adequately to cope 

 with all its ramifications, that in the absence of strict inquiry imposture has been 

 rampant in some portions of it for centuries, and that unless we are preternaturally 

 careful we may get led into quagmires if we venture on it at all. 



Now let me be more definite, and try to state what this field is, the explora- 

 tion of which is regarded as so dangerous. I might call it the borderland 

 of physics and psychology. I might call it the connection between life and 

 energy; or the connection between mind and matter. It is an intermediate region, 

 bounded on the north by psychology, on the south by physics, on the east by phy- 

 siology, and on the west by pathology and medicine. An occasional psychologist has 

 groped down into it and become a metaphysician. An occasional physicist has 

 wandered up into it and lost his base, to the horror of his quondam brethren. 

 Biologists mostly look at it askance, or deny its existence. A few medical practi- 

 tioners, after long maintenance of a similar attitude, have begun to annex a portion 

 of its western frontier. The whole region seems to be inhabited mainly by savages, 

 many of them, so far as we can judge from a distance, given to gross superstition. 

 It ma}', for all I know, have been hastily traversed and rudely surveyed by a few 

 clear-eyed travellers ; but their legends concerning it are not very credible, certainly 

 are not believed. 



Why not leave it to the metaphysicians F I say it has been left to them long 

 enough. They have explored it usually with insufficient equipment. The physical 

 knowledge of the great philosophers has been necessarily scanty ; and though the 

 ideas which we owe to their genius may ultimately be of the greatest service 

 to us as physicists, still their methods are not our methods. They may be said to 

 have floated a balloon over the region with a looking-glass attached, in which 

 they have caught queer and fragmentary glimpses. They may have seen more 

 than we give them credit for, but they appear to have guessed far more than they 

 saw. 



Our method is different. "VVe prefer to creep slowly from our base of physical 

 knowledge, to engineer carefully as we go, establishing forts, making roads, and 

 thoroughly exploring the country ; making a progress very slow, but very lasting. 

 The psychologists from their side may meet us. I hope they will ; but one or 

 other of us ought tO begin. 



A vulnerable spot on our side seems to be the connection between life and 

 energy. The conservation of energy has been so long established as to have become 

 a commonplace. The relation of life to energy is not imderstood. Life is not 

 energy, and the death of an animal affects the amount of energy no whit ; yet a 

 live animal exerts control over energj' which a dead one cannot. Life is a guiding 

 or directing principle, disturbing to the physical world but not yet given a place in 

 the scheme of physics. The transfer of energy is accounted for by the performance of 

 work ; the guidance of energy needs no work, but demands force only. What is 

 force ? and how can living beings exert it in the way they do ? As automata, 

 operated on by preceding conditions — that is, by the past — say the materialists. Are 

 we 80 sure that they are not controlled by the future too ? In other words, that the 



