Raymond Pearl letter to Karl Pearson, discussion of conflict between biometrical and experimental approaches to study heredity (3/12/1910) (1)

2134. (2) CID7 the method and I think that it is utterly fallacious [double underscore]as applied to problems of inheritance[end double underscore]. I hope I make myself clear upon this point. I desire to do so. I hope shortly to be able to publish a statement of the considerations which lead to the conclusions just expressed. The third alternative is that I do not believe in Mendelian theory. Such a statement is idle. I have as little sympathy with the great bulk of Mendelian [underscore]theory[end underscore] as you have. I [underscore]am[end underscore] exceedingly interested in Mendelian [underscore]facts[end underscore]. You say that you think it quite possible that I can misinterpret evidence and misjudge facts. This I should say is quite true, but I am not aware that I have any monopoly in this direction. Is it not just conceivably possible that you yourself may have some time or rather fallen into error in one or the other of these directions? Your implied denial of the [underscore]existence[end underscore] of pure lines is difficult to understand. . It appeals to me as very much the same sort of a proposition as someone attempting to defend the thesis that black is white. If you could see, as I have repeatedly seen, acres of ground covered with pure line pedigreed cultures showing all the characteristics which Johannsen describes for such pure lines, I am sure that you could not make such a statement as you do. The question of the existence of pure lines is not a question of opinion at all but a question of fact. If you will take the trouble to do so you can at any time see such pure lines. Within the pure lines their[sic] is no [obs text] reduction of the correlation in a geometrical progression as we go towards the higher ancestry whatever. [end]