Creator: The Wikipedia page refers to a range of Humanist Manifestos. This one was created in 1980 by the council for Secular Humanism, founded by Paul Kurtz.
Purpose: Wikipedia says “The central theme of all three manifestos is the elaboration of a philosophy and value system which does not necessarily include belief in any personal deity or “higher power”.
Secular Humanist Manifesto
1. Free Inquiry
2. Separation of Church and State
3. The Ideal of Freedom
4. Ethics Based on Critical Intelligence
5. Moral Education
6. Religious Skepticism
7. Reason
8. Science and Technology
9. Evolution
10. Education
Source
Humanist Manifesto on Wikipedia
Thanks to Helen Omand for suggesting this manifesto