If ever there was a spirit thoroughly invigorated by the "joy of right
understanding" it is that of the author of these pieces. Even the reader
catches something of his intellectual buoyancy, and is thus carried
almost lightly through discussions which would be hard and dry in the
hands of a less animated writer.... No less confident and serene than
his acceptance of the utmost logical results of recent scientific
discovery is Mr. Fiske's assurance that the foundations of spiritual
truths, so called, cannot possibly be shaken thereby.--_The Atlantic
Monthly_ (Boston).