Angelo Giuseppe Roncalli, "il Papa Buono"
A church building contains architectural elements that are common to all buildings; but also contains features making it identifiable as a church. One aspect of a “church-identity” is verticality in which the height of the church building will make it stand out from other structures, and also bring to mind the idea of “the heavens above” with the uplifting architectural motion of church design. The columns of a church play a key role in “supporting” the verticality of the structure by enabling greater height and openness in the interior.
On your next visit to a church, try to identify the type of columns that are used and notice how they assist in developing a feeling of uplift in the building.
The Column
A column is a pillar, usually with a rounded or rectangular shaft, with a capital on top and a base on the bottom. The main purpose of the column is to provide support, although some columns are present for decorative purposes. The columns support the entablature which is a horizontal beam between the columns supporting the overhead structure of a building. Columns were (and are) especially important for large structures in the absence of supporting arches; although, in some cases, they support arches themselves.
The three fundamental parts of a column are:
Shaft: A vertical pillar which may be circular, rectangular or polygonal. They are either uniform in diameter or taper toward the top or bottom. Many are fluted, i.e. have vertical grooves running from top to bottom which aid in making a column appear more perfectly round. A supporting column is attached to a capital on the top and base on the bottom. A rectangular decorative column that is attached to a wall is known as a pilaster.
Capital: The top part of the column that distributes the load of the building in a horizontal fashion from a column across the entablature (horizontal support/beam above) to adjacent columns. Capitals range from simple square blocks to highly decorated inverted bells. The form of the capital is the part of the column that most readily distinguishes the Architectural Order of the building (see below).
Base: The bottom part of the column supporting the load of the building. The rounded or rectangular base is larger in diameter than the shaft above to distribute the building weight over a larger area. Note: some types of classical columns (Doric) do not have a base, but rest directly on the pavement underneath a row of columns.
Architectural Orders
There are five types of architectural orders which can be readily identified by the features of the columns of a building. The five orders developed chronologically. The Doric, Ionic and Corinthian orders originated in Greece; while the Tuscan and Composite orders are Roman.
The following are characteristics of the columns of each order:
Doric: A tapered shaft (wider on the bottom than top) with a simple capital, no base and very shallow fluting. It is the shortest and stoutest of the classical column orders.
Ionic: A very slightly tapered shaft with more fluting than the Doric. The order is easily identified by the curved scrolls on the capital protruding to each side of the column. (See an example of Ionic columns in photo above.)
Corinthian: The most elegant of the orders with striking capitals adorned with acanthus leaves and scrolls. It is the tallest of the orders with the taper similar to the Ionic and slightly more fluting. In usage after ancient times, the capitals are typically gold-colored or gilded.
Tuscan: The order developed by the Romans that is similar to the Greek Doric order with a simple design, and no fluting, although slimmer in diameter than the Doric order with a limited taper.
Composite: As implied, this Roman design uses styles from other orders (Ionic and Corinthian) and is a slender, fluted shaft with a decorative capital using scrolls and acanthus leaves.
See an illustrated drawing, and examples, of each of the types of columns at https://churchwonders.com/architecture-and-symbolism/architectural-orders-and-columns/