bottom lines, bull's-eyes, centerpieces, cores, essences, gists, hearts, kernels, keynotes, meat and potatoes, meats, nets, nubbins, nubs, nuclei(also nucleuses), piths, pivots, points, roots, sums
courses, directions, drifts, tenorsbodies, contents, substanceshypotheses, propositions, purports, subjects, themes, theses