And wishing to show at greater length that even the thoughts of God entertained by the human race are not superior to those of all other mortal creatures, but that certain of the irrational animals are capable of thinking about Him regarding whom opinions so discordant have existed among the most acute of mankind— Greeks and Barbarians— he continues: “If, because man has been able to grasp the idea of God, he is deemed superior to the other animals, let those who hold this opinion know that this capacity will be claimed by many of the other animals; and with good reason: for what would any one maintain to be more divine than the power of foreknowing and predicting future events?
Men accordingly acquire the art from the other animals, and especially from birds. And those who listen to the indications furnished by them, become possessed of the gift of prophecy. If, then, birds, and the other prophetic animals, which are enabled by the gift of God to foreknow events, instruct us by means of signs, so much the nearer do they seem to be to the society of God, and to be endowed with greater wisdom, and to be more beloved by Him. The more intelligent of men, moreover, say that the animals hold meetings which are more sacred than our assemblies, and that they know what is said at these meetings, and show that in reality they possess this knowledge, when, having previously stated that the birds have declared their intention of departing to some particular place, and of doing this thing or the other, the truth of their assertions is established by the departure of the birds to the place in question, and by their doing what was foretold.
And no race of animals appears to be more observant of oaths than the elephants are, or to show greater devotion to divine things; and this, I presume, solely because they have some knowledge of God.” See here now how he at once lays hold of, and brings forward as acknowledged facts, questions which are the subject of dispute among those philosophers, not only among the Greeks, but also among the Barbarians, who have either discovered or learned from certain demons some things about birds of augury and other animals, by which certain prophetic intimations are said to be made to men.
For, in the first place, it has been disputed whether there is an art of augury, and, in general, a method of divination by animals, or not. And, in the second place, they who admit that there is an art of divination by birds, are not agreed about the manner of the divination; since some maintain that it is from certain demons or gods of divination that the animals receive their impulses to action— the birds to flights and sounds of different kinds, and the other animals to movements of one sort or another. Others, again, believe that their souls are more divine in their nature, and fitted to operations of that kind, which is a most incredible supposition.
Source: Against Celsus (New Advent)