Justin deals with the concept of reincarnation only once in his dialogue with Trypho, but his testimony is strong and clear. He presents his view on the doctrine early on in the dialogue as he introduces himself to his audience and answers their preliminary questions.

When Trypho asks Justin to describe his views on God and other matters of philosophy (Chapter 1), Justin recounts his philosophical wanderings and his subsequent conversion to Christianity (Chapters 2 and 3). This conversion was brought about, in part, by his meeting with an old man in a field by the sea, an unnamed Christian, who engages him in a conversation that quickly turns to matters of philosophy.

During this conversation, Justin reveals his belief in God and his support for Plato’s ideas on who He is (Chapter 3). Knowing this, the Christian raises challenges against a number of Plato’s doctrines – including the belief in the transmigration of the soul.

The old man starts his challenge by establishing Justin’s position on a number of issues:

1.According to Justin, the souls of man and animal are not necessarily incompatible.
2.Only a temperate and righteous man or a free soul can see God.
3.An animal cannot see God, due to the interference of its body.

All these points are conceded by the Christian for the sake of discussion.

He then moves on to his main argument, demonstrating two important points:

1.The fact that a man has seen God (or gained any other experience at all) has no positive (lasting) effect on him if he cannot remember this experience in his subsequent incarnations.
2.If a man does not know that he is being punished, he receives no true punishment. It profits him nothing then, if he is imprisoned in the body of a beast as a punishment for actions taken in a previous (and forgotten) incarnation.

Since, then, neither the previous incarnation nor the subsequent re-incarnation serve a proper purpose (they neither benefit the man as proper rewards, nor serve as proper punishments), they must be rejected altogether. If transmigrations really do occur, they must serve a purpose – but since no relevant purpose can be found to make this doctrine profitable, it cannot be logically held. Indeed, for this doctrine to have any merit at all, the reincarnated man must remember all of his previous incarnations, but this is clearly not the case.

Justin agrees with these conclusions and the men continue on in their discussion with other matters of philosophy, and then prophecy. When the two finally part, Justin professes that, “straightway a flame was kindled in my soul; and a love of the prophets, and of those men who are friends of Christ, possessed me; and whilst revolving his words in my mind, I found this philosophy alone to be safe and profitable” (Chapter 8).

It is evident from this account that Justin not only agreed, but continues to agree with the old man’s argument against the transmigration of the soul – otherwise, he would not have included this portion of their argument in the account of his conversion from Platonic philosophy to Christianity. This conclusion is further evidenced in Justin’s later references to the resurrection of the dead, and its universal application to both the righteous and the unrighteous (Chapter 117, cf. First Apology Chapters 8, 18, 52, etc.).

As the first Christian apologist, Justin’s work bears an important witness to the attitude of the early Christian Church on the doctrine of reincarnation. Not only is Justin’s personal testimony against the doctrine important here, but also his attestation of an earlier rejection of the doctrine by the Christians who preceded him.