The property or propositions from which a conclusion is drawn (8)
I believe the answer is:
premises
This clue could be a double definition.
'the property' is the first definition.
(I've seen this before)
'propositions from which a conclusion is drawn' is the second definition.
'premises' can be an answer for 'propositions' (premise is a kind of proposition). I am not sure about the remainder of the definition.
'or' acts as a link.
Can you help me to learn more?
(Other definitions for premises that I've seen before include "Building, place of business" , "establishment" , "House with its land" , "The aforesaid" , "Business buildings" .)