The application of the important criteria which Bower has thus pointed out to the construction of a strictly phylogenetic classification of the Filicaceae cannot be made until the anatomy, the sexual generation and the palaeobotanical evidence have been further examined from this point of view.
But more than this it is interesting as among the first works in which Greek history became a separate study, based on real evidence and governed by the criteria of modern historical science.
This question, however, will rest upon those criteria alone which are of true chronological validity (see further Genesis).
Success will depend on objective criteria and visualizing the process.
Water-cress, sweet flag, flowering rush, several potamogetons, water milfoil, water ranunculus, and the reedy sweet watergrass (Glyceria aquatica) rank amongst the criteria of excellence.
Astruc's criteria were too slight to give to all the details of his analysis anything approaching a final analysis; but later criticism has shown that his criteria, so far as they went, were valid, and his results, broadly speaking, sound though incomplete: and, moreover, they have abundantly justified his really important fundamental theory that the documents used by the compiler of the Pentateuch have been incorporated so much as they lay before him that we can get behind the compiler to the earlier sources and thus push back the evidence of much of the Pentateuch beyond the date of its compilation to the earlier date of the sources.
Finally, the conceptions of strength, power and masterfulness by which Nietzsche attempts to determine his own moral ideal, become, when examined, as relative and unsatisfactory as other criteria of moral action said to be deduced from evolutionary principles.
The vast advance in knowledge of the existing forms of living things that has been acquired and recorded since 1859 has accentuated the difficulty of finding any morphological criteria for species.
Poulton, in an admirable discussion of contemporary views regarding species (presidential address to the Entomological Society of London 1904), has shown that Darwin did not believe in the objective existence of species, not only because he was led to discard the hypothesis of special creation as the explanation of the polymorphism of life, but because in practice as a working systematist he could neither find for himself nor ascertain from other systematists any settled criteria by which a group of specimens could be elevated into a genus, accepted as a species, or regarded as a variety.
We have specific criteria and certain limitations.