What is the simplest ancient architectural order that does not contain a volute or acanthus leaves and whose column does not have a base?

The simplest ancient architectural order that fits this description is the Doric order. Characterized by its sturdy columns, the Doric style features a fluted shaft that rests directly on the stylobate, without a base. It is known for its simplicity and strength, lacking decorative elements such as volutes and acanthus leaves, which are found in later orders like the Ionic and Corinthian. The Doric capital is also quite plain, typically consisting of a rounded echinus and a square abacus.