The compass of accurate knowledge directs the shortest, safest, cheapest course to any destination
Human nature is perpetual. In most respects it is the same today as in the time of Caesar. So the principles of psychology are fixed and enduring
Address the people you seek, and them only
Changing people's habits is very expensive
If a claim is worth making, make it in the most impressive way.
Literary qualifications have no more to do with it than oratory has with salesmanship. One must be able to express himself briefly, clearly, and convincingly, just as a salesman must.