"Boutroux [...] believes he is criticising science, but instead he criticises a puppet of formal logic, as if the logical power of thought were exhausted in the principle of identity, A is A; but conversely, he establishes a dogmatism worse than the scientific one (because it is philosophical) by considering all reality as a posteriori of experience. (Guido De Ruggiero, La filosofia contemporanea, Editori Laterza, Bari, 19648, part II, Ch. IV, p. 192)"