When we descend to details, we can prove that no one species has changed (i.e., we cannot prove that a single species has changed): nor can we prove that the supposed changes are beneficial, which is the groundwork of the theory. Nor can we explain why some species have changed and others have not.


In: Francis Darwin (ed.), The Life and Letters of Charles Darwin (Volume 2)


When we descend to details, we can prove that no one species has changed (i.e., we cannot prove that a single species has changed): nor can we prove...

When we descend to details, we can prove that no one species has changed (i.e., we cannot prove that a single species has changed): nor can we prove...

When we descend to details, we can prove that no one species has changed (i.e., we cannot prove that a single species has changed): nor can we prove...

When we descend to details, we can prove that no one species has changed (i.e., we cannot prove that a single species has changed): nor can we prove...