Has this question, then, made so much progress, either to the profit of animals or the detriment of mankind, that we should wish to stop it, when it has started already on so straight a path? Saint Chrysostom reproached the Gentile philosopher, it is said, with having always been inclined to assimilate that which they called the soul of animals with that of man himself.[60] The opinion of these Gentiles, nevertheless, is worth the trouble of being noticed. They were as well able to observe animals as ourselves. Since then, the means of study, as applied to intellect, have made little or no progress; observation and reflection are still the same; we have found no new process, no new method, by which we can more profoundly examine into this subject; we have, then, no reason to think that the solutions given by ourselves upon this point are at all preferable to those of the ancients. It may be rather the contrary. For their opinion has this much in its favour, that it was born free, in minds which did not restrain, even unwittingly, any new influence or theory which might be brought forward.[61] The idea of the intellectual gradation from man to animals must have been necessarily offensive to Christianity, which promised a future existence; it was not so for these Gentiles, who were much more occupied with matters of the world.[62] The principles which we are endeavouring to revive are not, however, completely those of Aristotle. In his treatise on the soul he admits this gradation, but as presenting in each degree a new manifestation beyond the manifestations existing in the inferior degrees. The principle of the soul is unity; but as we reascend the series, from plants to man, it invests itself with a greatly increased number of faculties. Porphyrius, resuming the ideas of the Stagyrite, seems to go even further, and to approach nearer the truth; it is not faculties joined one to another that he recognises in man and animals, but the same in all, only more or less developed.[63] At the present day, if we have not returned to the ideas of Pythagoras and the Stoics, at least we are very far from Pereira and Descartes, with their _animal machines, hydraulic-pneumatic machines_, as one of the partisans of the Bréton philosopher (J. H. Crocius) calls them.[64] We are really astonished at the infatuation for the opinions of Descartes which took possession of Germany during the latter half of the seventeenth century. They were pushed to the extreme point,--soul, reason, and intellect were denied to all animals. A person named Stahl,[65] who had at least the merit of being consistent to the last, brings forward a principle, that animals do not feel, _bruta non sentire_. This announcement is the conclusion of a very learned syllogism, and which one Gaspard Laugenhert had added to the _Compendium Physicæ_ of Arnold Geulinx.