MY DEAR FRIEND: Among the many good things Mr. Harte has told me of you, two in particular gave me great pleasure. The first, that you are exceedingly careful and jealous of the dignity of your character; that is the sure and solid foundation upon which you must both stand and rise. A man's moral character is a more delicate thing than a woman's reputation of chastity. A slip or two may possibly be forgiven her, and her character may be clarified by subsequent and continued good conduct: but a man's moral character once tainted is irreparably destroyed. The second was, that you had acquired a most correct and extensive knowledge of foreign affairs, such as the history, the treaties, and the forms of government of the several countries of Europe. This sort of knowledge, little attended to here, will make you not only useful, but necessary, in your future destination, and carry you very far. He added that you wanted from hence some books relative to our laws and constitution, our colonies, and our commerce; of which you know less than of those of any other part of Europe. I will send you what short books I can find of that sort, to give you a general notion of those things: but you cannot have time to go into their depths at present-you cannot now engage with new folios; you and I will refer the constitutional part of this country to our meeting here, when we will enter seriously into it, and read the necessary books together. In the meantime, go on in the course you are in, of foreign matters; converse with ministers and others of every country, watch the transactions of every court, and endeavor to trace them up to their source. This, with your physics, your geometry, and your exercises, will be all that you can possibly have time for at Paris; for you must allow a great deal for company and pleasures: it is they that must give you those manners, that address, that 'tournure' of the 'beau monde', which will qualify you for your future destination. You must first please, in order to get the confidence, and consequently the secrets, of the courts and ministers for whom and with whom you negotiate.
I will send you by the first opportunity a short book written by Lord Bolingbroke, under the name of Sir John Oldcastle, containing remarks upon the history of England; which will give you a clear general notion of our constitution, and which will serve you, at the same time, like all Lord Bolingbroke's works, for a model of eloquence and style. I will also send you Sir Josiah Childe's little book upon trade, which may properly be called the "Commercial Grammar." He lays down the true principles of commerce, and his conclusions from them are generally very just.
Since you turn your thoughts a little toward trade and commerce, which I am very glad you do, I will recommend a French book to you, which you will easily get at Paris, and which I take to be the best book in the world of that kind: I mean the 'Dictionnaire de Commerce de Savory', in three volumes in folio; where you will find every one thing that relates to trade, commerce, specie, exchange, etc., most clearly stated; and not only relative to France, but to the whole world. You will easily suppose, that I do not advise you to read such a book 'tout de suite'; but I only mean that you should have it at hand, to have recourse to occasionally.
With this great stock of both useful and ornamental knowledge, which you have already acquired, and which, by your application and industry, you are daily increasing, you will lay such a solid foundation of future figure and fortune, that if you complete it by all the accomplishments of manners, graces, etc., I know nothing which you may not aim at, and in time hope for. Your great point at present at Paris, to which all other considerations must give way, is to become entirely a man of fashion: to be well-bred without ceremony, easy without negligence, steady and intrepid with modesty, genteel without affectation, insinuating without meanness, cheerful without being noisy, frank without indiscretion, and secret without mysteriousness; to know the proper time and place for whatever you say or do, and to do it with an air of condition all this is not so soon nor so easily learned as people imagine, but requires observation and time. The world is an immense folio, which demands a great deal of time and attention to be read and understood as it ought to be; you have not yet read above four or five pages of it; and you will have but barely time to dip now and then in other less important books.