E. E. Constance Jones and the Law of Significant Assertion

E. E. C. Jones (1848–1922), a Cambridge logician and Mistress of Girton College, is especially known for her Law of Significant Assertion, with which she tries to escape Hermann Lotze’s skepticism about categorical propositions. Her first formulation of it dates from 1890, and several philosophers have pointed out the similarities with Gottlob Frege’s use of Sinn and Bedeutung in 1891 and 1892. We argue that there are also important differences from Frege’s approach, and that Jones’s discovery relies on the traditional distinction between extension and intension. Although Bertrand Russell did not think highly of Jones’s views, he seems to have felt the pressure to discuss them in his paper “Knowledge by Acquaintance and Knowledge by Description” of 1911, where his criticism resembles the way he criticized Frege in “On Denoting” of 1905. We surmise that Russell’s argument against Jones may be questionable, since it is based on an assumption that Frege makes, but that Jones rejects.