Reverence for the dead is something essentially human and Christian– not a cultish attempt to communicate with the dead or better their lot in some practical way, but the recognition, however dim, that personality survives the death of the body, and so can be honored and dishonored after death (whether or not the dead are conscious of it isn’t really the issue).
Historical philosophy (the kind of work I do) can be seen as a way of showing reverence for the dead. If Socrates or Descartes showed up at Loyola with something to say, I would be disrespectful not to listen to them, whether or not I agreed. Likewise even for, say, Democritus or William of Auxerre. They are our intellectual fathers and older brothers and deserve a fair hearing. But they can’t request that hearing for themselves, because they’re dead. So they need people to speak up for them.
An objection: Philosophy is about the truth, not honoring people. The errors of deceased philosophers shouldn’t be promulgated merely because they’re deceased.
Reply: Of course not. If Socrates (for example) wanted to know the truth but taught something false, it would be dishonoring to Socrates to continue to teach his own, false beliefs. But first we have to study dead philosophers and see which of their teachings are true and which are false, a job which is by no means finished.
And before we decide which of their teachings are true, we have to understand those teachings on their own terms. That’s where the job of a historical philosopher is important.
And finally, while judging their teachings, we may find ourselves being judged by them, and our own convictions and conclusions questioned; and we may finally discover that the dead can still speak for themselves.