Saṅkapparāga, what an interesting word!
The aṭṭhakathā say:
saṅkapparāgoti saṅkappavasena uppannarāgo.
that is “saṅkapparāgo is lust (-rāga) which arose (uppanna-) due to (-vasena) thought/intention (saṅkappa-)” or in short “thought-arisen lust” or “intention-arisen lust”.
Similarly the aṭṭhakathā also say:
saṅkapparāgoti saṅkappitarāgo.
i.e. “saṅkapparāgo means saṅkappitarāgo“ whereas the ṭīkā say:
saṅkappitarāgoti subhādivasena saṅkappitavatthumhi rāgo.
i.e. “saṅkappitarāgo is lust (rāgo) for the intended (saṅkappita) object (vatthu) due to (-vasena) beauty (subha)”
It’s important to note that the -ita part of saṅkappita indicates a past participle, i.e. an action which was performed, in this case ‘thought out’, ‘intended’.
It’s true that sometimes saṅkappa could be translated as ‘concept’, but that not the same as what paññatti means in Buddhism. In fact the ‘concepts’ the article talks about are the kind of concepts which can be said to be paññatti. The Abhidhammatthasaṅgaha defines 8 groups or types of concepts.
Digging deeper the ṭīkā also say:
nimittānubyañjanāni saṅkappeti etenāti saṅkappo, tathāpavatto lobho, tato balavā rañjanaṭṭhena rāgo, saṅkappanavaseneva pavatto tatopi balavataro saṅkapparāgoti.
This cool commentary snippet describes the progression:
saṅkappa 🡒 lobha 🡒 rāga 🡒 saṅkapparāga
The PEA (Pāḷi English Abhidhāna) defines (nimittānubyañjana - Pāḷi English Abhidhāna) nimittānubyañjanāni as having to do with signs and characteristics of men/women, their beautiful features which give rise to defilements.
So the ṭīkā basically say - when you start thinking of pleasant stuff that’s called ‘thinking’ (saṅkappa) which gives rise to greed (lobha), but when taking delight there is strong lust (rāga), but even stronger than that is the saṅkapparāga which arises only due to thought. Saṅkappana here suggests achieving something through deliberate thought.
So the intentionality, the deliberateness of the thinking is the key, the act of thinking is the key, because it’s deliberate.
The linguistic and commentary journey aside, one of the best known uses of saṅkappa of course is sammāsaṅkappa (most widely translated as “right resolve” or “right thought”). It just makes no sense translating it as “right concept”.
In summary, for me, saṅkapparāga means “intentioned lust” or “intention of lust” rather than “love for concepts”.