228 Mind and Body 



as well as of the body. Whatever we may think of the 

 body-and-mind relation, the activities of the two are 

 in mundane experience inseparable. Perhaps the 

 mind plays on the body as the musician on his instru- 

 ment, and will naturally be affected if the body is 

 out of tune. Perhaps the inner and the outer life, the 

 psychical and the protoplasmic, the mental and the 

 metabolic, are two aspects of one activity. 



Perhaps and perhaps ; but the certainty is that the 

 reality we call "mind" and the reality we call "body" 

 are in intimate correlation. The cat is excited by the 

 impertinence of the dog ; its emotion, akin to anger, 

 affects the sympathetic nervous system; this stimu- 

 lates the supra-renal bodies to increased production of 

 adrenalin; this affects the whole of the cat's body — 

 from its heart to its hair, which stands on end. But if 

 this be taken as an instance of mind affecting body 

 through the mediacy of the endocrine (or internal 

 secretion) glands, we must also recognize that the 

 activity of the glands may influence the mind. Exces- 

 sive thyroid activity may be the background of boast- 

 ing ; thyroid insufficiency may be the cause of mental 

 depression. An animal with a relatively large supra- 

 renal cortex is likely to be aggressive and courageous, 

 whereas one with a relatively small supra-renal cortex 

 is likely to be timid and self-effacing. 



In an interesting, if sometimes impetuous, book, 

 The Glands Regulating Personality, Dr. Louis Ber- 

 man pictures a number of types of men who are in 

 the sway of particular endocrine glands. There is the 

 adrenal personality — vigorous, efficient, forceful, apt 



