WASHINGTON, Aug. 19 - Senator Bill Frist of Tennessee, the Republican leader, aligned himself with President Bush on Friday when he said that the theory of intelligent design as well as evolution should be taught in public schools.

Such an approach "doesn't force any particular theory on anyone," Mr. Frist said in Nashville, according to The Associated Press. "I think in a pluralistic society that is the fairest way to go about education and training people for the future." A Washington spokesman for the senator, Nick Smith, said later that the report was accurate.

The theory of intelligent design holds that life is too complicated to have developed through evolution and that a higher power must be involved. Critics say intelligent design theorists are trying to supplant science with religious beliefs.

The senator's view, expressed after his speech at a Rotary Club meeting, echoed President Bush's remarks of Aug. 2, when he told Texas newspaper reporters that he favored teaching both evolution and intelligent design "so people can understand what the debate is about."

Mr. Frist's agreement with President Bush on one of the more contentious educational, social and political issues of the time comes just a few weeks after he broke with Mr. Bush and with Christian conservatives on embryonic stem cell research.

The senator said on July 29 that he supported a bill to expand federal financing for stem cell research, and that President Bush's four-year-old policy of strictly limiting taxpayer financing "should be modified." The bill has been approved by the House but has been stalled in the Senate.

Mr. Frist is widely assumed to be contemplating a run for the presidency in 2008, so his statements on issues that touch on moral as well as political questions are sure to be scrutinized both by Christian conservatives essential to a Republican candidacy and by people looking for signals that Mr. Frist is willing to move toward the center.

Human embryonic stem cells can grow into any type of body tissue, so scientists and doctors see a potential use in treating a wide variety of diseases and injuries. But the cells cannot be obtained without destroying the embryos, which some people say is tantamount to murder.