Two Doric columns from the
Temple of Poseidon at Paestum
showing Entasis 

Entasis can be defined as a slight convex curve in the shaft of a column or pillar. Entasis was introduced as a corrective system to counter the visual illusion of concavity produced by a straight shaft.

In architectural terms, entasis can be considered to be the application of a convex curve to a surface for what can be described as essentially aesthetic purposes. Entasis was often applied to columns during classical antiquity, particularly the Doric order and occasionally the Ionic order. The columns used to articulate temple facades would curve slightly as their diameter is decreased from the bottom of the column upwards. Some columns, as evident in the picture, would be at their widest at a point above the base of the column, however this method appears aesthetically displeasing for the viewer.

Entasis was an architectural system devised to combat the optical illusion created by viewing a column from a distance at a viewpoint which is often lower than the foot of the column.

Key periods in history where entasis was applies:

• Classical Greece.
• Hellenistic era.
• Roman period.

Entasis Definition - Ancient Greek Temple Architecture

The Caryatid Porch of the Erechtheion,
Athens,  421-407 B.C.

A Caryatid is a stone carving of a draped female figure, which is used both as a decorative architectural feature and primarily as a column to support the entablature of a an ancient Greek temple. Or for a Grecian-style building which emulates various motifs inspired by classical architecture.

Caryatids Definition - Ancient Architecture

The Doric Order,
The Temple of Poseidon
At Paestum 460 450 B.C

The Doric order is the oldest and most simplistic of the ancient orders. The Doric order was both robust and imposing; and was therefore deemed to be suitable for use in temple architecture. The columns of the Doric order and are often without bases. The shafts of the Doric order's columns are articulated with concave curves called flutes.

The capitals of the Doric order have a rounded section at the bottom which is called the echinus and the capital is surmounted by a square at the top which is called the abacus. The capitals of the doric order are plain and are often unadorned.

The composition of the Doric order's entablature is: a frieze with alternating vertical channels, known as Triglyphs. The architrave rests upon the capital of the column. The frieze and architrave are separated by a thin band called the regula. The frieze, architrave and regula form a large and distinctive part of a temple's form. The Doric order has been put to use in many notable buildings of ancient antiquity such as the Parthenon.

On the left is part of a Doric entablature and column. On the right is a plan of the Parthenon
With two rows of columns on the entrances.

Doric Order Definition

The types of orders used in the architecture of antiquity are:

• Doric Order
• Ionic Order
• Corinthian Order
• Tuscan Order
• Byzantine Order
• Composite Order; often a combination of the first three orders' best characteristics.

Types of Classical Orders - used in the architecture of antiquity

An Example of the Ionic Order

The ionic order forms one of the three orders, also referred to as organisational systems of classical architecture. Namely Greek and Roman architecture. The order was developed by the Greeks for their temple architecture. The name ionic is derived from the Ionian Islands where the style of architecture was first employed. (Read more after Break)

Ionic Order Definition

When an object, subject or artwork is described as antique, especially with regard to an art historical context, it relates to the classical world of antiquity. When looking specifically at Europe and Asia-minor a work from antiquity, an antique, comes from/emanates from the Greco-Roman civilization. Antique artworks, architecture, literature and remnants of ancient cultures were often used by later Renaissance painters as a source for inspiration during the classical rebirth - which was the Renaissance.Antique - Art Definition

Parthenon Temple Facade, close up of Frieze
Click to enlarge image

Greek Temple Frieze - Parthenon

The Parthenon is a temple on the Acropolis in Athens
Dating to around 430BC
Click to enlarge image

Greek Temple Architecture - The anatomy of the Parthenon Temple on the Acropolis

Classicizing is a broad artistic term used to describe any period of history which attempts to reintroduce features of Greco-Roman art and architecture from antiquity, namely using ancient subject matter or re-applying motifs.

Related term see article on all'antica

What is meant by the term Classicising