Translated by Cardinal Newman. Cf. An introduction to Athanasius' treatise Against the Heathen
Against the Heathen.
1. Introduction:--The purpose of the book a vindication of Christian doctrine, and especially of the Cross, against the scoffing objection of Gentiles. The effects of this doctrine its main vindication.
The knowledge of our religion and of the truth of things is independently manifest rather than in need of human teachers, for almost day by day it asserts itself by facts, and manifests itself brighter than the sun by the doctrine of Christ. 2. Still, as you nevertheless desire to hear about it, Macarius  , come let us as we may be able set forth a few points of the faith of Christ: able though you are to find it out from the divine oracles, but yet generously desiring to hear from others as well. 3. For although the sacred and inspired Scriptures are sufficient  to declare the truth,--while there are other works of our blessed teachers  compiled for this purpose, if he meet with which a man will gain some knowledge of the interpretation of the Scriptures, and be able to learn what he wishes to know,--still, as we have not at present in our hands the compositions of our teachers, we must communicate in writing to you what we learned from them,--the faith, namely, of Christ the Saviour; lest any should hold cheap the doctrine taught among us, or think faith. in Christ unreasonable. For this is what the Gentiles traduce and scoff at, and laugh loudly at us, insisting on the one fact of the Cross of Christ; and it is just here that one must pity their want of sense, because when they traduce the Cross of Christ they do not see that its power has filled all the world, and that by it the effects of the knowledge of God are made manifest to all. 4. For they would not have scoffed at such a fact, had they, too, been men who genuinely gave heed to His divine Nature. On the contrary, they in their turn would have recognised this man as Saviour of the world, and that the Cross has been not a disaster, but a healing of Creation. 5. For if after the Cross all idolatry was overthrown, while every manifestation of demons is driven away by this Sign  , and Christ alone is worshipped and the Father known through Him, and, while gainsayers are put to shame, He daily invisibly wins over the souls of these gainsayers  ,--how, one might fairly ask them, is it still open to us to regard the matter as human, instead of confessing that He Who ascended the Cross is Word of God and Saviour of the World? But these men seem to me quite as bad as one who should traduce the sun when covered by clouds, while yet wondering at his light, seeing how the whole of creation is illumined by him. 6. For as the light is noble, and the sun, the chief cause of light, is nobler still, so, as it is a divine thing for the whole world to be filled with his knowledge, it follows that the orderer and chief cause of such an achievement is God and the Word of God. 7. We speak then as lies within our power, first refuting the ignorance of the unbelieving; so that what is false being refuted, the truth may then shine forth of itself, and that you yourself, friend, may be reassured that you have believed what is true, and in coming to know Christ have not been deceived. Moreover, I think it becoming to discourse to you, as a lover of Christ, about Christ, since I am sure that you rate faith in and knowledge of Him above anything else whatsoever.
 See de Incarn. 1 and note there.
 Constantly insisted on by Athan. Cf. de Incarn. 5, and note on de Decr. 32.
 De Incarn. 56. 2; he may also be referring to works from the Alex. school, such as Orig. de Princ.
 Cf. de Incarn. 47. 2, 48. 3, Vit. Ant. passim.
 Cf. de Incarn. 50. 3, 51. 3, &c.
Reference address : https://www.elpenor.org/athanasius/contra-gentes.asp