To strive for a position upon some loftier eminence, and yet to remain unruffled if those strivings are in vain; to remain calm and cheerful within the little circle where Providence has stationed us, yet actively endeavoring to enlarge that circle, if not to obtain admittance to a higher one; to plume the pinions of the soul for an upward flight, yet calmly sink again to the earth if these efforts are but useless flutterings; all this seems contradictory, though essential to perfection of character. Thankfulness for what we have, yet longings for a greater boon; resignation to a humble lot, and a determination that it shall not always be humble; ambition and contentment--how wide the difference, and how difficult for one breast to harbor them both at the same time! Nothing so forcibly convinces us of the frailty of humanity as the tendency of all that is good and beautiful to corruption. As in the natural world, earth's loveliest things are those which yield most easily to blighting and decay, so in the spiritual, the noblest feelings and powers are closely linked to some dark passion. How easily does ambition become rapacity; and if the heart's yearnings for the unattainable are forcibly stilled, and the mind is governed by the determination that no wish shall be indulged but for that already in its power, how soon and easily may it sink into the torpor of inaction! To keep all the faculties in healthful exercise, yet always to restrain the feverish glow, must require a constant and vigilant self-command. How soon, in that long-past sacred time when the Savior dwelt on earth, did the zeal of one woman in her Master's cause become tainted with the earth-born wish that her sons might be placed, the one upon his right and the other upon his left hand, when he should sit upon his throne of glory; and how soon was _their_ ardent love mingled with the fiery zeal which would call down fire from heaven upon the heads of their fellow-men! Here was ambition, but not a justifiable desire for elevation; an ambition, also, which had its source in some of the noblest feelings of the soul, and which, when directed by the pure principles which afterwards guided their conduct, was the heart-spring of deeds which shall claim the admiration, and spur to emulous exertions, the men of all coming time. "Be content with what ye have," but never with what ye are; for the wish to be perfect, "even as our Father in heaven is perfect," must ever be mingled with regrets for the follies and frailties which our weak nature seems to have entailed upon us. And while we endeavor to be submissive, cheerful, and contented with the lot marked out for us, may gratitude arouse us to the noble desire to render ourselves worthy of a nobler station than earth can ever present us, even to a place upon our Savior's right hand in his heavenly kingdom. H. F. A CONVERSATION ON PHYSIOLOGY. INTRODUCTION.