M. Mouret is not one of those scholars that lack hospitality for other writings than those of their own nationality. From this fault so noticeable in the work of so many of the French scholars M. Mouret himself seems to be free. Indeed so far as regards the previous work done in the domain he sets himself to examine, he accords almost exclusive esteem to the writings of English thinkers. In fact he declares himself so far as regards his present topic a disciple of Mr. Herbert Spencer and puts his “axiom of symmetry” as an adaptation of that maxim of his said master which is of the tenor as follows, viz: “_Things which have a definite relation to the same thing have a definite relation to one another._” This maxim, as Mr. Spencer tells us, was suggested to him by a remark of the late eminent author who is known to the world under the pseudonym of George Eliot, who herself stated it under the form “_Things that have a constant relation to the same thing have a constant relation to each other._” Those who are well acquainted with the psychology of Mr. Spencer will recognise that this maxim of his is made by him the very backbone of all his observations upon reasoning. If it has the validity which he imputes to it, it has an importance which it will be hard to overestimate, but if on the contrary, and as we shall submit, it is in every form in which it has been stated, certainly unsound and misleading, it is high time that its virtue should be brought into question. The _dicta_ of the masters whether they first enounce the same or whether they only give currency thereto by their ratification are always proper subjects for special scrutiny. There is always found a disposition to accept them on their mere _ipse dixit_ without any attempt at criticism or independent observation. This is decisively _not_ the scientific mood or mode. The spirit of that modern leaven that is currently referred to under the name of Science is characteristically a critical one, and one that is considerably irreverent in regard to the authority of mere personality. In this it is happily distinguished from the spirit that has marked the past history of what may be called the “regular” schools of philosophy. M. Mouret is not alone in his inadvertent esteem for the maxim in question. In the issue of _Mind_ for October 1891 Mr. L. T. Hobhouse publishes an article entitled “Induction and Deduction,” in which he gives an undue appraisal to the worth of the maxim under consideration, even though the author of the article seems to be well aware that said maxim stands in much need of qualification. We venture to say that this maxim in all its forms has gained whatever currency it has enjoyed in virtue alone of the incompetent comprehension that too generally prevails in regard to the nature and characteristics of that sort of things that are relations.