"A little inaccuracy more or less does not affect the analogy. For the sake of my picture I should like to retain the conception-couple, _variable_ and _invariant_. Well, then, the species give our savant the impression of invariance, as in the view that was held by Linné and Cuvier. This view necessarily has its counterpart in his thought. He argues that every species has its own original root, and that, in this sense, there is very extensive variation. The fundamental roots are extremely manifold; Nature has produced innumerable variations in her individual acts of creation. But now the _Theory of Descent_ of Lamarck, Goethe, Oken, Geoffroy St. Hilaire, enters the field and produces a complete inversion of these two elements; the two parts of the earlier point of view change places. Our savant has to revise his whole world of thought. Now all organisms are to be traced back to a single original root: the latter, which was variable before, becomes an invariable unicellular primitive organism, but the apparently unchangeable species now becomes variable, in the widest possible sense. And even if this savant should exclaim: 'How am I to reconcile myself to this view?' his descendants later find no difficulty in accepting the idea that the organic roots are uniform, and that it is the species that are subject to all manner of variation as a compensating feature." Einstein expressed himself very little pleased with this attempt at an analogy, and found that it was so far fetched that it could not be considered admissible.