Is the sigmatic future related to the sigmatic aorist?

Question

When I was learning Ancient Greek, I was taught that most verbs had three basic stems corresponding to the different aspects: imperfective -λυ-, aoristic -λυσ-, and perfective -λελυκ-. Adding an augment made them past-tense, removing it made them non-past.

This was a useful mnemonic. But historically, was there actually any connection between the sigmas in the future λύσ-ω ("non-past aoristic") and the aorist ἔ-λυσ-α ("past aoristic")? I had always assumed so, but then I came across the "S-future" while researching the Latin future perfect.

Answer 1

They're almost certainly not related.

The sigmatic aorist occurs in several Indo-European branches and is reconstructed to Proto-Indo-European. The sigmatic future isn't reconstructed to PIE -- in fact, PIE seems to have had no future tense at all. Instead, the sigmatic future is thought to come from a PIE desiderative form (with the meaning "want to [verb]"). In some branches this desiderative underwent a semantic change to become a future tense marker -- just like English will, which used to mean "want to".

As far as I know there's no reason to think that the sigmatic aorist and the desiderative were related in PIE, despite their similarity (which may be partial -- the desiderative suffix may have been not just -s- but -h₁s-, with a laryngeal).

(Btw teaching that there are "three basic stems" in Greek isn't very good pedagogy because lots of verbs form their future and aorist from different stems. And I don't know that the Greek future can be defined as "non-past aoristic" -- it can have non-aoristic/imperfective aspect too.)