His case relies heavily on science. Nine affidavits from scientists that were part of the court filings offer opinions of what research says about the lives, thinking ability and self-awareness of chimpanzees.

Mr. Wise argues that chimps are enough like humans that they should have some legal rights; not the right to vote or freedom of religion — he is not aiming for a full-blown planet of the apes — but a limited right to bodily liberty. The suits asked that the chimps be freed to go to sanctuaries where they would have more freedom.

Richard L. Cupp, a law professor at Pepperdine University in California who opposes granting rights to nonhuman animals, described the legal strategy as “far outside the mainstream.” He said in an email, “The courts would have to dramatically expand existing common law for the cases to succeed.”

Lori Marino of Emory University, who studies dolphins and other cetaceans and is the science director of the Nonhuman Rights Project, said it “is about more than these four chimpanzees.” Mr. Wise, she said, “sees this as the knob that can turn a lot of things. It’s potentially transformative.”

She said she was under no illusion that rights for animals would be easy to gain. “It may not happen in anyone’s lifetime,” she said.