by peculiar marks among themselves, they seem to converse: they also appear to have a kind of smile, when with soothed ears, and contracted mouth, and with eyes relaxed to sportiveness, they fawn upon man, or upon their own mates and young. Do they not give a greeting which bears some resemblance to mutual love and indulgence? Again, those creatures which look forward to the future and lay up for themselves food, plainly have foresight. Indications of reason are also found in many of them. For since they desire things useful to themselves, guard against evils, avoid dangers, prepare for themselves lurking-places standing open in different places with various outlets, assuredly they have some understanding. Can any one deny that they are possessed of reason, since they often deceive man himself? For those which have the office of producing honey, when they inhabit the place assigned to them, fortify a camp, construct dwellings with unspeakable skill, and obey their king; I know not if there is not in them perfect prudence. It is therefore uncertain whether those things which are given to man are common to him with other living creatures: they are certainly without religion. I indeed thus judge, that reason is given to all animals, but to the dumb creatures only for the protection of life, to man also for its prolongation. And because reason itself is perfect in man, it is named wisdom, which renders man distinguished in this respect, that to him alone it is given to comprehend divine things. And concerning this the opinion of Cicero is true: "Of so many kinds of animals," he says, "there is none except man which has any knowledge of God; and among men themselves, there is no nation either so uncivilized or so savage, which, even if it is ignorant of due conceptions of the Deity, does not know that some conception of Him ought to be entertained." From which it is effected, that he acknowledges God, who, as it were, calls to mind the source from which he is sprung. Those philosophers, therefore, who wish to free the mind from all fear, take away even religion, and thus deprive man of his peculiar and surpassing good, which is distinct from living uprightly, and from everything connected with man, because God, who made all living creatures subject to man, also made man subject to Himself. What reason is there why they should also maintain that the mind is to be turned in the same direction to which the countenance is raised? For if we must look to the heaven, it is undoubtedly for no other reason than on account of religion; if religion is taken away, we have nothing to do with the heaven. Therefore we must either look in that direction or bend down to the earth. We are not able to bend down to the earth, even if we should wish, since our posture is upright. We must therefore look up to the heaven, to which the nature of the body calls us. And if it is admitted that this must be done, it must either be done with this view, that we may devote ourselves to religion, or that we may know the nature of the heavenly objects. But we cannot by any means know the nature of the heavenly objects, because nothing of that kind can be found out by reflection, as I have before shown. We must therefore devote ourselves to religion, and he who does not undertake this prostrates himself to the ground, and, imitating the life of the brutes, abdicates the office of man. Therefore the ignorant are more wise; for although they err in choosing religion, yet they remember their own nature and condition.
 The sounds uttered by the beasts, by which they are able to distinguish one another. [Rousseau's theory goes further.]