This is the seventh part of an article in nine pieces.
 

Evaluation of the sources

1. Independent confirmation: when an author who is not primarily interested in Apollonius confirms something in a source on Apollonius, we may assume that we are approaching the historical truth.
2. Multiple attestation: when independent, pre-Philostratean traditions about Apollonius are in agreement, we may be reasonably certain that they contain some historical truth. The problem with this method is, of course, that it is not always easy to establish independence.
3. Embarrassment: embarrassing  information about the man from Tyana also has a claim to historical reliability.
4. Consistency: sometimes the truth of statement can be confirmed after other facts have been established.

• Apollonius was considered a magician. Independent confirmation: it is taken for granted by Cassius Dio, Lucian (the latter referring to a disciple) and Anastasius Sinaitica [note 8]. Fourfold attestation: to be found in the Reminiscences of Moeragenes, in the memoirs of Damis, in the Letters of Apollonius, and in the Antiochene tradition. Embarrassment: Philostratus clearly felt uncomfortable with this, and three times offers apologies.
• Apollonius performed healings. Independent confirmation: taken for granted by Cassius Dio, Lucian (both referring to Apollonius' disciples) and Anastasius Sinaitica [note 8]. Fivefold attestation: to be found in the infancy narrative by Maximus of Aegae, in the Tyanean tradition, the story about the plague in Ephesus, the story of the rabies patient in Tarsus, and in Damis.
• Apollonius lived in the second half of the first century. Independent confirmation: Lucian mentions a disciple of Apollonius who lived in the first half of the second century. Sixfold attestation: Moeragenes, Letters of Apollonius (especially 58, a consolation of a Roman governor whose governorship can be dated in 82/83), Damis, Anastasius Sinaitica [note 8], mentioned by one Domninus [note 9]. Consistency: Apollonius must have been a contemporary of Euphrates of Tyre (and Domitian).
• Apollonius was a neo-Pythagorean philosopher. Independent attestation: Lucian, Life of Alexander. Fourfold attestation: to be found in the Letters of Apollonius, implied in the title of one Apollonius' publications, to be found in Damis, which presupposes a conflict with Stoicism and Cynicism. Consistency: the ideas expressed in the fragment of On sacrifices resemble what is known of first century Pythagoreanism [note 10].
• Apollonius wrote a book On sacrifices. This cannot be established by the criteria used, but  it is quoted by Porphyry.
• Apollonius wrote a book On astrology. Twofold  attestation: On astrology is mentioned by Moeragenes and Damis. Embarrassment: Philostratus expresses his disbelief about the existence of On astrology.

• Apollonius wrote a book on Pythagoras' doctrines (or a biography). Independent confirmation: Probably used by Iamblichus and Porphyry.
• Apollonius traveled to India. Threefold attestation: Damis, Letter 59, mentioned in Porphyry, The Styx [note 11]. (Independent confirmation from India remains possible.)
• Apollonius traveled to Egypt. Twofold attestation: Damis, John Malalas.

• Apollonius could predict the future: Twofold attestation: Mentioned in the Ephesian tradition and Damis. Embarrassment: Philostratus tries to explain this away.
• Euphrates of Tyre and Apollonius were quarreling.  Threefold attestation: To be found in the Letters of Apollonius; Moeragenes and Damis tell the same story.
• Apollonius tried to reform certain cultic practices. Twofold attestation: First, there is the quote from On sacrifices;  furthermore, it is expressed in the Letters of Apollonius.
• The story of Apollonius' vision of the murder of Domitian: Independent confirmation: Philostratus has picked up the story in Ephesus, and Cassius Dio tells it too.
• The story about the birds' language:  Independent confirmation: Philostratus claims to have heard this story at Ephesus and there is a different account of it in Porphyry's treatise On abstinence.
• Apollonius' relation to the common cults was strained: Embarrassment: Philostratus tries to explain away failures (at the oracle of Trophonius, at Eleusis, and on Crete).

• Apollonius was a champion of Greek culture. Only to be found in the Letters of Apollonius.
• Apollonius traveled to Spain: Only to be found in Damis .

Apollonius and his contemporaries

On the other hand, many ancient philosophers did model their lives to earlier examples. For example, when the Roman philosopher Seneca was forced to commit suicide, he choose to imitate Socrates by drinking hemlock. We will never know who was responsible for the philosophical anecdotes in the LoA, the Tyanean or his biographer.

Another problem is the parallelism of the lives of Apollonius and Pythagoras. In other sources, Pythagoras is said to have been initiated in all religious rites and mysteries, to have descended in a cave, to have visited Babylon and Egypt, to have been able to remember former incarnations, to have abstained from wine and meat, to have worn a special dress, to have kept a vow of silence for five years, to have been on two places at the same time, to have confronted a tyrant, and to have died in a temple at a venerable old age. For all these stories, we find parallels in the LoA [note 12].

There are three explanations for these parallels:

1. It may be that Philostratus or one of his sources has modeled the life of Apollonius to the life of Pythagoras. 
2. It may be the other way round, because many stories about the life of Pythagoras were written after the death of Apollonius.
3. Another explanation is that Apollonius imitated Pythagoras.

A final problem is what to make of elements that are without parallel. To repeat an earlier example, Philostratus frequently mentions Apollonius' prayers to the sun, something for which we do not find antecedents in the Pythagorean literature. Maybe, Philostratus found this information in one of his sources, or maybe, he invented it, because it was a popular theme in the third century. In this case, the first alternative is to be preferred, because the second option would imply that Philostratus read some contemporary philosophers, which is extremely unlikely.

Another example is Apollonius' abstinence from sex. This is really unprecedented in Greek society, and the inevitable conclusion is that Apollonius of Tyana has invented celibacy.