Celsus, however, seeing he wished to prove by the foregoing statements that the irrational animals are more divine and intelligent than human beings, ought to have established at greater length the actual existence of such an art of divination, and in the next place have energetically undertaken its defence, and effectually refuted the arguments of those who would annihilate such arts of divination, and have overturned in a convincing manner also the arguments of those who say that it is from demons or from gods that animals receive the movements which lead them to divination, and to have proved in the next place that the soul of irrational animals is more divine than that of man.
For, had he done so, and manifested a philosophical spirit in dealing with such things, we should to the best of our power have met his confident assertions, refuting in the first place the allegation that irrational animals are wiser than men, and showing the falsity of the statement that they have ideas of God more sacred than ours, and that they hold among themselves certain sacred assemblies. But now, on the contrary, he who accuses us because we believe in the Supreme God, requires us to believe that the souls of birds entertain ideas of God more divine and distinct than those of men.
Yet if this is true, the birds have clearer ideas of God than Celsus himself; and it is not matter of surprise that it should be so with him, who so greatly depreciates human beings. Nay, so far as Celsus can make it appear, the birds possess grander and more divine ideas than, I do not say we Christians do, or than the Jews, who use the same Scriptures with ourselves, but even than are possessed by the theologians among the Greeks, for they were only human beings. According to Celsus, indeed, the tribe of birds that practise divination, forsooth, understand the nature of the Divine Being better than Pherecydes, and Pythagoras, and Socrates and Plato!
We ought then to go to the birds as our teachers, in order that as, according to the view of Celsus, they instruct us by their power of divination in the knowledge of future events, so also they may free men from doubts regarding the Divine Being, by imparting to them the clear ideas which they have obtained respecting Him! It follows, accordingly, that Celsus, who regards birds as superior to men, ought to employ them as his instructors, and not one of the Greek philosophers.
Source: Against Celsus (New Advent)