The so-called Augustus of Primaporta was clearly made to provide visible testament to Augustus's claim to authority and the creation of a visual language of imperial images. Augustus holds in his left hand a spear which was a symbol of ability in arms and power (imperii). The spear, which will morph into the scepter of the medieval king, was a regular symbol of imperial power. Augustus is shown wearing the cuirass, or breastplate of a military general. This manifests Augustus's role as imperator, or head of Rome's military forces. The formula of the cuirass statue would be one of the most prevalent in the Roman tradition. For example see Harvard's Arthur M. Sackler Museum statue of the Emperor Trajan. A coin from the reign of Valens in the middle of the fourth century exemplifies the continuity of this formula. Along with the cuirass, a common characteristic of this portrait type is the contrapposto pose with the weight clearly shifted to one leg. Scholars have seen a special reference in this pose in the statue of Augustus. They have seen strong parallels to the statue entitled the Doryphoros by the Greek mid fifth-century BCE artist Polykleitos. This statue was one of the most famous and most copied statues of Antiquity. A copy in Naples gives us some sense of the lost original. Literary references to this statue make it clear that Polykleitos intended this statue to be a visual demonstration of his canon of ideal man. The similarities between the two statues extend beyond the poses to the handling of facial details. Both emphasize the clear delineation of the brow and nose. Similar conventions are used in the handling of the hair of both. It was undoubtedly intentional on the part of the Augustan artists to base their statue on the Greek work. The rich drapery with its multiple-folds and elegant edge can be related to Greek Classical drapery style like that appearing on the Parthenon. Both the Doryphoros and the Augustus of Primaporta share the same calm, self-controiled expression. Using the Greek distinction, both represent the ethos, or character, of the figures rather than their pathos, or immediate emotional response. The conception of the ideal man of the Greek Classical period was an important model for Augustus, the ideal man of his age, but there is the significant difference that the Augustus statue is unmistakably a portrait of Augustus while the Doryphoros like the other major Greek works is a representation of the archetypal concept of the male figure and clearly not a representation of a particular individual.
Beyond the standardization of type, a striking feature of the Augustus statue and imperial portraiture in general is the standardization in the representation of the individual emperors. While the portraits of Augustus are easily identifiable by the facial features, the artists were clearly not interested in representing Augustus at different stages of his life. Portraits of Augustus are not 'realistic' at all and bear little resemblance to the description of him given by Suetonius (Augustus 79-82). There are no portraits of a sixty year old Augustus. Like the Augustus of Primaporta, the portraits show Augustus at the prime of his life.
Another significant difference between the Polykleitos statue and the Augustus of Primaporta is how the Doryphoros is self-contained in its balanced pose while the right arm of the Augustus of Primaporta extends out in space. This is one of the most popular and easily identifiable gestures in Roman art, the ad locutio gesture or the gesture of speech. In Roman public life, the orator played a central role. The ability to convince an audience through an effective oration was critical to the success of a politician. For a military leader, the ability to rally and motivate the army was a hallmark of a great general. The ad locutio gesture conveys of the voice and authority of the figure.
The importance of the orator in Roman public life explains the central role of rhetoric in Roman education. A good rhetorician would learn to adapt his style to the appropriate context. A good rhetorician would know to use a simpler, plainer style for certain audiences while using a higher, more eloquent style in more formal and sophisticated contexts. He also would know how to quote respected authorities to lend support to an argument. There is thus an important parallel between rhetoric and the design of Augustan statuary. It was clearly intentional to adapt the Classical Greek style and specific reference to the famed statue by Polykleitos in creating the Augustus of Primaporta. What scholars call Augustan classicism relates the period of Augustus to the great period of Greek culture of the fifth century BCE, the so-called age of Pericles and the period of the Parthenon.
Individual details of the statue serve to reinforce the claims and ambitions of Augustus. Attached to the right foot of Augustus and serving as a support for the statue is a representation of a cupid riding on the back of a dolphin. As stated in the prophesy from the Aeneid cited above, Augustus traced his ancestry back to Aeneas and the foundation of the Roman tradition. Aeneas was understood to have been the off-spring of the goddess Venus like the Cupid who rides the back of the dolphin. This geneaology was central to his claim to be princeps and pater patriae. Patriarchal family structure was the bedrock of Roman society. The Roman elite of the Senatorial class owed their status not to their personal accomplishments but to the authority of their family. By basing his claim to authority on his geneaology which links him to the first family of Rome, Augustus was appealing to traditional Roman values. He again constructed himself as a conserver and rennovator and definitely not as an innovator.
The decoration of the cuirass places a specific event in the context of a Roman vision of the world. At the center of the relief, there is a barbarian figure clearly identifiable by pants and beard handing a Roman military standard to a man dressed on a Roman cuirass. While there is no certainty as to the identification of the Roman in the scene, the barbarian is identifiable as a Parthian, perhaps their king Phraates IV, who returned the Roman standards in 20 BCE that the Parthians had captured in 53 BCE after the defeat of Crassus. Significantly this victory was a diplomatic and not a military one, and was heralded as an important step in establishing the era of Augustan peace. Other figures on this cuirass bring out the universal implications of this event. At the top appears a bearded figure holding a veil over his head. This is Caelus, or the Sky god, with the mantle of the heavens. Beneath this figure appears a figure driving a four-horse chariot. This is the sun-god Sol. The chariot is preceded and appears to chase a figure identified as Aurora. Flanking the central group are again two female figures. The one on the left has been identified as Hispania (Spain) while the other has been suggested to be Gallia. Beneath these figures are the brother and sister pair of Apollo, with a lyre and riding a griffin, and Diana, riding a stag. At the very bottom of the cuirass appears the reclining female figure Tellus who holds a cornucopia and is accompanied by two babies. This imagery gives Roman rule divine sanction to rule everything under the heavens from Spain to Gaul and everything over the Earth. It is important to acknowledge the gender politics of this cuirass with the male Sol driving out female Aurora. The provinces and earth are personfied as female with the active male figures at the center of the composition. The imagery of the cuirass clearly relates to one of the odes of Horace.