Full Idea
Something must exist, then, and have qualities, without being itself either a quality or a relation. And this is Substance.
Gist of Idea
Substance has to exist, with no intrinsic qualities or relations
Source
J.M.E. McTaggart (The Nature of Existence vol.1 [1921], §67), quoted by R.D. Ingthorsson - A Powerful Particulars View of Causation 7.2
Book Reference
'Oxford Handbook of Philosophy of Time', ed/tr. Callender,Craig [OUP 2013], p.109
A Reaction
Ingthorsson quotes this as 'the most extreme analytic view', which is a long way from the Aristotelian view. This is the implausible bare substrate.