Based on Benjamin Franklin's 13 Virtues System:

"I propos’d to myself, for the sake of clearness, to use rather more names, with fewer ideas annex’d to each, than a few names with more ideas; and I included under thirteen names of virtues all that at that time occurr’d to me as necessary or desirable, and annexed to each a short precept, which fully express’d the extent I gave to its meaning." - Benjamin Franklin