permitted himself to be discouraged by the reflection that we cannot all be _Newtons_. It is our business to make the most of our own talents and opportunities, and instead of discouraging ourselves by comparisons and imaginary impossibilities, to believe all things possible--as indeed almost all things are, to a spirit bravely and firmly resolved. Franklin was a fine model of _a practical man_ as contradistinguished from a _visionary theorist_, as men of genius are very apt to be. He was great in that greatest of all good qualities, _sound, strong, common sense_. A mere book-worm is a miserable driveller; and a mere genius, a thing of gossamer fit only for the winds to sport with. Direct your intellectual efforts, principally, to the cultivation of the strong, masculine qualities of the mind. Learn (I repeat it) _to think_--_to think deeply, comprehensibly, powerfully_--and learn the simple, nervous language which is appropriate to that kind of thinking. Read the legal and political arguments of Chief Justice Marshall, and those of Alexander Hamilton, which are coming out. Read them, _study them_; and observe with what an omnipotent sweep of thought they range over the whole field of every subject they take in hand--and _that_ with a scythe so ample, and so keen, that not a straw is left standing behind them. Brace yourself up to these great efforts. Strike for this giant character of mind, and leave prettiness and frivolity for triflers. There is nothing in your letter that suggests the necessity of this admonition; I make it merely with reference to that tendency to efflorescence which I have occasionally heard charged to southern genius. It is perfectly consistent with these herculean habits of thinking, to be a laborious student, and to know all that books can teach. This extensive acquisition is necessary, not only to teach you how far science has advanced in every direction, and where the _terra incognita_ begins, into which genius is to direct its future discoveries, but to teach you also the strength and the weakness of the human intellect--how far it is permitted us to go, and where the penetration of man is forced, by its own impotence and the nature of the subject, to give up the pursuit;--and when you have mastered all the past conquests of science, you will understand what Socrates meant by saying, that he knew only enough to be sure that _he knew nothing--nothing, compared with that illimitable tract that lies beyond the reach of our faculties_. You must never be satisfied with the surface of things: probe them to the bottom, and let nothing go 'till you understand it as thoroughly as your powers will enable you. Seize the moment of excited curiosity on any subject to solve your doubts; for if you let it pass, the desire may never return, and you may remain in ignorance. The habits which I have been recommending are not merely for college, but for life. Franklin's habits of constant