Source: pp 367-368, The semantics of ‘empty prepositions’ in French (1996) by Kemmer and Shyldkrot, as part of Cognitive Linguistics in the Redwoods: The Expansion of a New Paradigm in Linguistics edited by Eugene H. Casad.
[1.] Although infinitive constructions always
involve an intrinisic relationbetween the action of the main verb and the action coded by the infinitive,
[2.] only de explicitly makes reference to that relationship.
Thus, the semantics of de make it appropriate to occur in the infinitive construction. However, it will only occur there where some more specific relationship, such as that coded by à, is lacking.
[3.] De, in contrast to à, has a much more abstract or semantically "bare-bones" meaning; it refers solely to an
of an unspecified type.
À makes no overt reference to this relation; its semantic specifications are simply different. Of all the French prepositions, à and de have semantic specifications that are most compatible with the relation between a main verb and an infinitive; this is why these two are the principal prepositions occurring in this construction, and are syn- chronically and diachronically in competition. We discuss this competition further in Section 5.
To me, 2 and 3 contradict each other. How (per 2) can de explicitly refer to a relationship,
if (per 3) the
of an unspecified type?
What special relationship or reference does de reveal? I am confused; 2 appears to distinguish de from 1's general statement that all infinitive constructions already
involve an intrinisic relation; but then 3 appears to evade specifying semantically this distinction, with vague modifiers such as 'much more abstract or semantically "bare-bones"'.