Why do schools teach evolution and the Big Bang but not intelligent design?

Answer 1

Answer

Evolution and the Big Bang are much more testable than intelligent design. Not that that necessarily makes one right and the other wrong, but the former are supported by the generally accepted scientific method of collecting evidence and putting it to the test.

Evolution and the Big Bang are not nearly as cleanly testable as a chemistry experiment showing that sodium + chlorine makes table salt, because there's no way to run the clock back and run a truly controlled experiment on them. In both cases you have to propose a hypothesis then see what it implies. Modern cosmology is on pretty solid ground because you can calculate what would happen if it were true. Not that it's perfect. There are some mighty weird fudge factors needed to make things turn out right.

Evolutionary theory is less solid, perhaps, but as a framework it sure explains an awful lot. Even if it's wrong it's worth understanding, otherwise you pretty much get stuck saying that everything is just a miracle, which is the same as saying that there is no explanation.

Where the trouble comes in is the logical leap from, "chickens and wrens share a common ancestor" to "I am master of the universe, and there are no consequences."

Answer

The US Supreme Court determined, in Edwards v. Aguillard, 482 US 578 (1987), that intelligent design can't be taught in public schools because it has its basis in creationism, a religious concept.

Public schools are prohibited from teaching religion under the Establishment Clause of the First Amendment, sometimes called "separation of church and state," which forbids the enactment of any law "respecting an establishment of religion." The Establishment Clause is designed to protect individual rights "to select any religious faith or none at all" (Wallace v. Jaffree, 472 US 52 (1985)).

Public schools are funded by taxpayer dollars, so they are also bound by the Establishment Clause. Even if the school were funded entirely through state and local tax money (which it's not), the states are also bound by the Establishment Clause through the Fourteenth Amendment, which selectively applies most of the Bill of Rights to the states.

In determining whether a statute violates the first amendment by promoting religion, the Court applies the three-prong "Lemon" test, developed in the case Lemon v. Kurtzman, 403 US 602 (1971).

1. The law must be enacted with a clear secular (non-religious) purpose.
   
   
2. The primary effect of the law cannot be to promote the belief that a "supernatural being created mankind."
   
   
3. The law cannot entangle the interests of church and state by seeking "the symbolic and financial support of government to achieve a religious purpose."