And, if we would ascertain the practical purport of this lesson of human diversity which is so conspicuous in the street--the meaning of these sharp contrasts of refinement and grossness, intelligence and ignorance, respectability and guilt--we only ask a question that thousands have asked before us. And yet, it is possible to surmise the purpose of these diversities. We know, for one thing, that out of them come some of the noblest instances of character and of achievement. Ignorance and crime and poverty and vice, stand in fearful contrast to knowledge and integrity and wealth and purity; but they likewise constitute the dark background against which the virtues of human life stand out in radiant relief; virtues developed by the struggle which they create; virtues which seem impossible without their co-existence. For, whence issues any such thing as _virtue_, except out of the temptation and antagonism of vice? How could _Charity_ ever have appeared in the world, were there no dark ways to be trodden by its bright feet, and no suffering and sadness to require its aid? I look at these asylums, these hospitals, these ragged schools--a zodiac of beautiful charities, girdling all this selfishness and sin--I look at these monuments which humanity will honor when war shall be but a legend, and laurels have withered to dust; and when I think what they have grown out of, and why they stand here, I regard them as so many sublime way-marks by which Providence unfolds its purposes among men, and by which men trace out the plan of God. And then, again, perhaps this problem of human diversity presses heaviest where civilization is the most advanced, in order that men may be more sharply aroused to seek some practical solution. It is an encouraging sign when an evil begins to be intensely felt, and the demand for relief becomes desperate. The civilization of our time is imperfect; involves many incongruities; perhaps creates some evils; but that it is an improved civilization, is evinced by the fact that it is _self-conscious_; for perception is the necessary antecedent of endeavor and success. The contrasts of human condition, then, that unfold themselves in the crowded street, may teach us our duty and our responsibility in lessening social inequality and need.