motif

subject matter

talking point

count, idea, point, purpose

consideration, issue, problem

body, bulk, burden, centerpiece, core, crux, essence, fundamental, generality, gist, grist, heart, kernel, keynote, main, marrow, mass, net, nub, nubbin, nucleus, pith, pivot, purport, quick, staple, substance, sum

basis

bottom, essential, essentiality

affair, argument, debate

scheme

device

adornment, caparison, decoration, embellishment, frill, garnish, ornament, trim