on the Influence of Diet on the Avian Death-rate. 355


to the controversy has any better reason to allege for its

opinions than the somewhat vague one that they have observed

a heavy death rate, or on the contrary have not experienced any

increase in mortality, after the use of the food for the time being

in dispute. They often go on to say, with the object of

strengthening their position, that the experience of a lifetime

bears them out in whichever opinion they hold.


But it is obvious that of two men, imbued with diame¬

trically opposite beliefs on one and the same narrow subject, both

cannot be right: they are more likely r to be both wrong. When

you find one section of aviculturists never giving x and another

section always giving it to their respective birds, and when you

find the death rate in neither section shewing any appreciable

improvement, does it not point irrefragibly to the conclusion that

they are both of them needlessly quarrelling over some¬

thing that is really outside the scope of their practical politics,

and that they should rather seek for some cause of the high

mortality which is common to both parties and which has

hitherto never been suspected by either of them? When we see

enteritis (inflammation of the mucous lining of the bowels)

accounted for by half-a-dozen different men, all equally honest

and all equally desirous of helping their fellows, on the score of

half-a-dozen different so-called errors in feeding, each of which

in the eyes of the other five appears to be harmless, (though the

enteritis still continues), what does this confusion point to in the

eyes of the rational onlooker? Exactly what I have said

before—that while it is evident that all of them cannot be right

it is quite possible, and indeed more than probable, that all of

them are wrong. Again, if all of them cannot be right, and one

of them is, which of them is it? And he that is right should be

able to definitely prove the stability of the position he takes up.

As the matter stands each has only the one and the same

argument, namely, that of experience, in other words “post hocA

and this he wishes to convert into “ propter hoc." Therefore, as

far as such argument as he has at command goes, each one is

equally right, which is an absurdity, as Euclid puts it in his

terse and felicitous terms.


Happily, however, the microscope has ended the con¬

fusion. It has shewn explicitly and indisputably that errors in



