Thread:GetYourFix/@comment-28532419-20160523125554/@comment-27907368-20160523225508

Hmm... I think it's canon that monsters do have SOULs - just most of them turn to dust on kill! That's why there's so many white monsters SOULs at the end of the Asriel fight.

However, we're unsure if Sans has a SOUL for certain - he likely does, though. Sans and Papyrus both have unique death animations (Sans has red stuff, Papyrus dusts in two pieces)... I wish we had an explanation for these things. T_T

In Undertale, though, it's not certain the boundary between living and not living - Flowey is soulless and still manages to do his thing. T_T