Thus he lived secluded from publick business, in contention with his father, in alienation from his wife.  This state of uneasiness he found the only means of softening.  He diverted his mind from the scenes about him, by studies and liberal amusements.  The studies of princes seldom produce great effects, for princes draw with meaner mortals the lot of understanding; and since of many students not more than one can be hoped to advance far towards perfection, it is scarcely to be expected that we should find that one a prince; that the desire of science should overpower in any mind the love of pleasure, when it is always present, or always within call; that laborious meditation should be preferred in the days of youth to amusements and festivity; or that perseverance should press forward in contempt of flattery; and that he, in whom moderate acquisitions would be extolled as prodigies, should exact from himself that excellence of which the whole world conspires to spare him the necessity.

In every great performance, perhaps in every great character, part is the gift of nature, part the contribution of accident, and part, very often not the greatest part, the effect of voluntary election, and regular design.  The king of Prussia was undoubtedly born with more than common abilities; but that he has cultivated them with more than common diligence, was probably the effect of his peculiar condition, of that which he then considered as cruelty and misfortune.

In this long interval of unhappiness and obscurity, he acquired skill in the mathematical sciences, such as is said to have put him on the level with those who have made them the business of their lives.  This is, probably, to say too much:  the acquisitions of kings are always magnified.  His skill in poetry and in the French language has been loudly praised by Voltaire, a judge without exception, if his honesty were equal to his knowledge.  Musick he not only understands, but practises on the German flute, in the highest perfection; so that, according to the regal censure of Philip of Macedon, he may be ashamed to play so well.

He may be said to owe to the difficulties of his youth an advantage less frequently obtained by princes than literature and mathematicks.  The necessity of passing his time without pomp, and of partaking of the pleasures and labours of a lower station, made him acquainted with the various forms of life, and with the genuine passions, interests, desires, and distresses, of mankind.  Kings, without this help from temporary infelicity, see the world in a mist, which magnifies every thing near them, and bounds their view to a narrow compass, which few are able to extend by the mere force of curiosity.  I have always thought that what Cromwell had more than our lawful kings, he owed to the private condition in which he first entered the world, and in which he long continued:  in that state he learned his art of secret transaction, and the knowledge by which he was able to oppose zeal to zeal, and make one enthusiast destroy another.