To think is difficult, and they who wish to grow in power of thought must hoard their strength. Excess, of whatever kind, is a waste of intellectual force. The weakness of men of genius has impoverished the world. Sensual indulgence diminishes spiritual insight; it perverts reason, and deadens love; it enfeebles the physical man, and weakens the organs of sense, which are the avenues of the soul. The higher self is developed harmoniously only when it springs from a healthful body. It is the lack of moral balance which makes genius akin to madness. Nothing is so sane as reason, and great minds fall from truth only when they fail in the strength which comes of righteous conduct. Let the lover of wisdom then strive to live in a healthy body that his senses may report truly of the universe in which he dwells. But this is not easy; for mental labor exhausts, and if the vital forces are still further diminished by dissipation, disease and premature decay of the intellectual faculties will be the result. The ideal of culture embraces the whole man, physical, moral, religious, and intellectual; and the loss of health or morality or faith cannot but impede the harmonious development of the mind itself. Passion is the foe of reason, and may easily become strong enough to extinguish its light. He who wishes to educate himself must learn to resist the desires of his lower nature, which if indulged deaden sensibility, weaken the will, take from the imagination its freshness, and from the heart the power of loving. The task he has set himself is arduous, and he cannot have too much energy, too much warmth of soul, too much capacity for labor. Let him not waste, like a mere animal, the strength which was given him that he might learn to know and love infinite truth and beauty. The dwelling with one's self and with thoughts of what is true and high, which is an essential condition of mental growth, is impossible when the sanctuary of the soul is filled with unclean images. Intellectual honesty, the disinterested love of truth, without which no progress can be made, will hardly be found in those who are the slaves of unworthy passions. The more religious a man is, the more does he believe in the worth and sacredness of truth, and the more willing does he become to throw all his energies with persevering diligence into the work of self-improvement. They who fail to see in the universe an all-wise, all-holy, and all-powerful Being, from whom are all things and to whom all things turn, easily come to doubt whether it holds anything of true worth. History teaches this, and it requires little reflection to perceive that it must be so. Of the Solitary, Wordsworth says,--