Many scientists believe that ID proponents are abandoning scientific inquiry and the scientific method by invoking design.
However, some of the most vocal supporters of intelligent design have scientific backgrounds and credentials. Prominent among them is Michael J. Behe, a professor of biological sciences at Lehigh University. Behe stresses that he regards ID as a "minimalist position. It only requires that there be physical evidence of an intelligence behind creation of complex natural systems. Who did the creating, or why, comprise a separate set of questions."
Among ID proponents, there are distinctions between those who support the "old Earth position" as Behe does—he believes that the universe is 13 billion years old—and proponents of the "young Earth" position. They all share a set of assumptions about the "irreducible complexity" of some natural phenomena, if not the process of the design or the characteristics of the designer.
