The Parthenon is a prime example of a Greek temple. It was built in honor of Athena Parthenos (Athena as a warrior). The temple houses the statue of the goddess and protects it from the weather. It did not hold crowds of worshippers; only a single altar, outside, was necessary for worship.
The Parthenon was constructed using two architectural orders, Doric and Ionic. The temple is basically Doric, but Ionic features were incorporated into it. It has an eight column peristyle, and a continuous Ionic style frieze along the outside of the naos. The combining of styles symbolizes the joining of Greek city-states to form the Delian League. The league was formed to keep out a Persian reinvasion.
The philosophy of the time is also revealed in the architecture of the Parthenon. Democritus stated that there was one substance that everything was made of, and Pythagoras believed that numbers were the basic element of the cosmos. These ideas can be seen through the proportion and measure of the temple. There was a common unit of measure called intercolumniation that was used for the whole structure. It was the distance between the center of one column to the center of the column next to it. A column was two intercolumniations tall, and the combined length of triglyph and metope was half an intercolumniation. Also, most measurements were linked in a ratio of 9:4, keeping the temple well-proportioned.
The influence of politics and philosophy continued over time. About 800 years after the Parthenon, the same aspects influenced the architecture of the Early Christian churches.
The church was built so that Christians would have a place to worship. However, during the Period of Persecution, Christians had to worship in secret. They would worship in the atrium style houses of wealthy Christians, bury their dead in catacombs, and perform secret ceremonies in catacomb chapels. This affected the way later churches would be built. The columnade of the atrium style houses appeared in the early church, as well as an apse with an altar. The Church of St. Peter is like this, and his remains are buried beneath the apse, like in a catacomb.
During the Period of Recognition, Christianity was accepted by Constantine. Christians were appointed to high offices in the Imperial government. This can be seen in St. Peter's through the division of the interior to house the people at one end, and the clergy at the other.
Early Christian beliefs also began influencing architecture. The belief in one god caused there to be only one apse, with a single altar. Christians believed that the site of Jesus' birth, death and resurrection was important. So the church was oriented so that the altar faced east (towards Jerusalem, the holiest city). They also believed that the crucifixion of Christ redeemed man. A bird's eye view of the church reveals a cross-like shape. Jesus attacked materialism with his Sermon on the Mount. The empty walls and depthless, lightless mosaics clearly show this.
The influences of political events and the beliefs of people on architecture has lasted since the early days of the Parthenon. They can be seen today in our banks and churches.