22 To what, then, you ask, do these things tend? We have brought them forward in order that— as it has been believed that the souls of men are divine, and therefore immortal, and that they come to their human bodies with all knowledge— we may make trial from this child, whom we have supposed to be brought up in this way, whether this is credible, or has been rashly believed and taken for granted, in consequence of deceitful anticipation.
Let us suppose, then, that be grows up, reared in a secluded, lonely spot, spending as many, years as you choose, twenty or thirty—nay, let him be brought into the assemblies of men when he has lived through forty years; and if it is true that he is a part of the divine essence, and lives here sprung from the fountains of life, before he makes acquaint-ante with anything, or is made familiar with human speech, let him be questioned and answer who he is, or from what father in what regions he was born, how or in what way brought up; with what work or business he has been engaged during the former part of his life.
Will he not, then, stand speechless, with less wit and sense than any beast, block, stone? Will he not, when brought into contact with strange and previously unknown things, be above all ignorant of himself? If you ask, will he be able to say what the sun is, the earth, seas, stars, clouds, mist, showers. thunder, snow. hail? Will he be able to know what trees are, herbs, or grasses, a bull, a horse, or ram, a camel, elephant, or kite?
Source: Against the Heathen (New Advent)