WHAT IS A DISEASE? 417 



it is always a group of things. Even in such a case as neuralgia, 

 the pain alone is not the disease. Neuralgia, considered as 

 pain et prater ea nihil, is a symptom. Neuralgia the disease 

 is more than this : it is the symptom plus a postulated intra- 

 corporeal cause, and it is the correlation of the symptom 

 with an underlying cause that converts the symptom into a 

 disease. A disease is an individual thing, but it is always a 

 compound thing, and it is compounded by the mental opera- 

 tion of the observer. The constituents of the disease exist 

 separately in the body and mind of the patient. Their com- 

 bination into a whole is effected in and by the mind of the 

 contemplator, and consists in the way in which he contemplates 

 them. The constituents of the disease are either parted in 

 space, like the clot in the brain and the paralysis of the limbs ; 

 or they are parted in time, like the hot fit and the cold fit of 

 ague ; or they are parted in nature, like the pain and the 

 swelling of inflammation. The several factors that go to make 

 up a disease are separate things, which in the patient exist 

 apart, and have no unity until they are combined in the mind 

 of the observer by his mental operation. The disorders are 

 disorders of the same person, but in him they are not one, but 

 many. What unity they have, other than what is imposed 

 by the causal nexus, is a conceptual unity, a mental grouping, 

 not a material propinquity. A disease is a group of things, 

 but the things are collected together, not in space, nor in 

 time, but in the mind of the observer. A disease is a mental 

 construct, and exists, not in the patient, but in the mind of 

 the observer only. What exists in the patient is not a disease, 

 but one or many disorders of function. 



When we speak of a disease attacking a person, we are 

 using a convenient figure of speech, but a figure of speech only. 

 The person is attacked by bacteria, or protozoa, or what not ; 

 but he cannot be attacked by that which has no existence 

 except in the mind of the observer. We may speak of a 

 disease as arising within or affecting a person, but what arises 

 in him and affects him is not a disease, but a disorder of some 

 function, which is not a disease until the idea of it is com- 

 bined in the mind of the observer with other ideas. The 

 patient suffers also from the consequences and symptoms of 

 this disorder of function ; but these consequences and symp- 

 toms are not the disease. It is the combination of them all that 



