Pope Benedict XVI said cooperation between science and faith is necessary for world peace and man's destiny, as he addressed the Pontifical Academy of Sciences this morning.

"I am convinced of the urgent need for continued dialogue and cooperation between the worlds of science and of faith in the building of a culture of respect for man, for human dignity and freedom, for the future of our human family and for the long-term sustainable development of our planet," he said in a speech given Nov. 8 at Clementine Hall.

"Without this necessary interplay, the great questions of humanity leave the domain of reason and truth, and are abandoned to the irrational, to myth, or to indifference, with great damage to humanity itself, to world peace and to our ultimate destiny."

This morning the Pope received in audience the participants in the Plenary Assembly of the Pontifical Academy of Sciences, which took place Nov. 5-7. The theme was "Complexity and Analogy in Science: Theoretical, Methodological, and Epistemological Aspects."

About 70 scientists, philosophers, and theologians – most of them members of the academy – participated in the Plenary Session and many are joining in a following Nov. 8-10 working group on "Neurosciences and the Human Person: New Perspectives on Human Activities."

Pope Benedict said the topics of complexity and analogy in science point toward "a new vision of the unity of the sciences." The gift of reason allows man to "constantly expand his knowledge of truth and order it wisely for his good and that of his environment."

"An interdisciplinary approach to complexity also shows too that the sciences are not intellectual worlds disconnected from one another and from reality," he said, "but rather that they are interconnected and directed to the study of nature as a unified, intelligible and harmonious reality in its undoubted complexity."

This in turn shows the complementarity of scientific study with philosophy and theology in the Christian tradition.

The idea of "participated being" in Christian thought is a "fruitful point of contact" with complexity and analogy in science.

Participated being holds that "each individual creature, possessed of its proper perfection, also shares in a specific nature and this within an ordered cosmos originating in God's creative Word."

"It is precisely this inbuilt 'logical' and 'analogical' organization of nature that encourages scientific research and draws the human mind to discover the horizontal co-participation between beings and the transcendental participation by the First Being."

The assembly examined the intelligibility of nature from a variety of perspectives, ranging from physics and maths, to environmental sciences, to free will and neuroscience, to the origins of the human mind.

Pope Benedict concluded by thanking the Pontifical Academy of Sciences for its efforts in strengthening the relationship between reason and faith, and drew their attention to the Year of Faith.