“It is,” says Professor Mathews, “only by continued, strenuous efforts, repeated again and again, day after day, week after week, and month after month, that the ability can be acquired to fasten the mind to one subject, however abstract or knotty, to the exclusion of everything else.”

“It is,” says Professor Mathews, “only by continued, strenuous efforts, repeated again and again, day after day, week after week, and month after month, that the ability can be acquired to fasten the mind to one subject, however abstract or knotty, to the exclusion of everything else.”

— Orison Swett Marden