Our Gemara on Amud Beis discusses the importance of quoting a teaching in the name of the sage who stated it:

“Rabbi Yochanan said in the name of Rabbi Shimon ben Yochai: With regard to any Torah scholar in whose name a matter of halacha is stated in this world, his lips move with the words in the grave, as though he were speaking.”

The simple reading of the Gemara implies that it is necessary to state the rabbi’s name in order to create the spiritual energy that channels and arouses the departed rabbi’s spirit so that “his lips will move,” as if he is saying the Torah.

However, the Chida (Chomas Anakh, Tehillim 40) discusses whether a person who writes a sefer anonymously benefits from this effect or not, since his name is not mentioned, albeit people are still studying his Torah. The Chida asserts that even an anonymous sefer achieves the same effect for the author, as Hashem knows who taught this Torah, even if others do not know. Why then is there an obligation to quote a teaching’s source? The Chida says this is for the practical reason that if the source is known it will be more respected, and therefore it encourages more people to study it.

How did the Chida understand our Gemara? It must be as follows: when a deceased person’s Torah is contemplated (regardless of whether it is in his name or not), it arouses his spirit, and it is as if he is saying it himself. However, in order to achieve that serious level of contemplation, we want what is being taught to be valued. Therefore, saying it in the person’s name, especially if it is a great sage, will increase the chances that it will be reviewed and internalized, and that is what is necessary to arouse the deceased person’s soul. It is not enough that his Torah will be casually mentioned; those hearing it must study it and be actively engaged in it.

The idea itself, that the deceased person’s spirit is aroused by engaging in their Torah, can be understood on a simple level: that a person’s greatest immortality is his ideas. If we are discussing their ideas, then it is as if they are still alive, because their effects remain in this world.

However, there is a deeper way to understand this as well. The idea of the soul recognizes that intellectual activity itself is the human soul. That is, the spark of autonomous, self-aware, intellectual activity represents a unique spiritual existence and manifestation. This sense of self, that we are who we are, is something subjective but not possible to explain scientifically. Everyone can feel and know themselves. What is that? Presumably, a robot can behave in programmed ways but not actually know itself and be aware of itself. This is the seat of intellect and the soul that the ancients were aware of. This was not a matter of faith but rather common sense and experience that made it obvious that the soul existed. What else could explain what was going on in everyone’s hearts and minds? “Science” has decided that what cannot be seen or proven objectively is not true, even though subjective experience is clear and that there is a sense of self that transcends wiring and neurons. We are who we are and we know it.

Therefore, when one’s Torah is being stated, it is as if he lives through those words. (For more about this, see Torah Temimah, Shir HaShirim 7:10.)