Painting by Katarina Countiss and Mike O.
Excerpt from Parallel Worlds: A Journey through Creation, Higher Dimensions, and the Future of the Cosmos by Kaku, Michio (Book – 2005) page 248.
Physicist Don Page has summarized the various forms of the anthropic principle that have been proposed over the years:
Weak anthropic principle: “What we observe about the universe is restricted by the requirement of our existence as observers.”
Strong-weak anthropic principle: “In at least one world… of the many-worlds universe, life must develop.”
Strong anthropic principle: “The undverse must have the properties for life to develop at some time within it.”
Final anthropic principle: “Intelligence must develop within the universe and then never die out.”