"...The Church can regard no one as excluded from its motherly embrace, no one as outside the scope of its motherly care. It has no enemies except those who wish to make themselves such. Its catholicity is no idle boast. It was not for nothing that it received its mission to foster love, unity and peace among men...Though We speak firmly and clearly in defence of religion, and of those human, spiritual values which it proclaims and cherishes, Our pastoral solicitude nevertheless prompts Us to probe into the mind of the modern atheist, in an effort to understand the reasons for his mental turmoil and his denial of God. They are obviously many and complex, and we must come to a prudent decision about them, and answer them effectively. They sometimes spring from the demand for a more profound and purer presentation of religious truth, and an objection to forms of language and worship which somehow fall short of the ideal. These things we must remedy. We must do all we can to purify them and make them express more adequately the sacred reality of which they are the signs. We see these men serving a demanding and often a noble cause, fired with enthusiasm and idealism, dreaming of justice and progress and striving for a social order which they conceive of as the ultimate of perfection, and all but divine. This, for them, is the Absolute and the Necessary. It proves that nothing can tear from their hearts their yearning for God, the first and final cause of all things. It is the task of our teaching Office to reveal to them, with patience and wisdom, that all these things are immanent in human nature and transcend it. Again we see these men taking pains to work out scientific explanation of the universe by human reasoning, and they are often quite ingenuously enthusiastic about this. It is an enquiry which is all the less reprehensible in that it follows rules of logic very similar to those which are taught in the best schools of philosophy...They are sometimes men of great breadth of mind, impatient with the mediocrity and self-seeking which infects so much of modern society. They are quick to make use of sentiments and expressions found in our Gospel, referring to the brotherhood of man, mutual aid, and human compassion...We do not therefore give up hope of the eventual possibility of a dialogue between these men and the Church..."
- ECCLESIAM SUAM, ENCYCLICAL OF POPE PAUL VI , AUGUST 6, 1964