The dissipation of thought of which you complain, is nothing more than the vacillation of a mind suspended between different motives, and changing its direction as any motive gains or loses strength. If you can kindle in your mind any strong desire, if you can but keep predominant any wish for some particular excellence or attainment, the gusts of imagination will break away, without any effect upon your conduct, and commonly without any traces left upon the memory. Depravity is not very easily overcome.
Nothing is difficult, when gain and honour unite their influence.
No man will be found in whose mind airy motions do not sometimes tyrannize, and force him to hope or fear beyond the limits of sober probability. He often perceives himself transported, he knows not how, to distant tracts of thought, and returns to his first object as from a dream, without knowing when he forsook it, or how long he has been abstracted from it. Many impose upon the world, and many upon themselves, by an appearance of severe and exemplary diligence, when they, in reality, give themselves up to the luxury of fancy, please their minds with regulating the past or planning out the future, place themselves at will in varied situations of happiness, and slumber away their days in voluntary visions. In the journey of life, some are left behind because they are naturally feeble and slow, some because they miss the way, and many because they leave it by choice, and, instead of pressing onward with a steady pace, delight themselves with momentary deviations, turn aside to pluck every flower, and repose in every shade.