I. Know then thyself, presume not God to scan,[1110] The proper study of mankind is man.[1111] Placed on this isthmus of a middle state,[1112] A being darkly wise, and rudely great: With too much knowledge for the sceptic side,[1113] 5 With too much weakness for the stoic's pride,[1114] He hangs between; in doubt to act, or rest;[1115] In doubt to deem himself a god or beast;[1116] In doubt his mind or body to prefer; Born but to die, and reas'ning but to err;[1117] 10 Alike in ignorance, his reason such,[1118] Whether he thinks too little or too much;[1119] Chaos of thought and passion, all confused;[1120] Still by himself abused,[1121] or disabused; Created half to rise, and half to fall;[1122] 15 Great lord of all things, yet a prey to all; Sole judge of truth, in endless error hurled; The glory, jest, and riddle of the world![1123] [1124]Go, wondrous creature! mount[1125] where science guides, Go, measure earth, weigh air, and state the tides; 20 Instruct the planets in what orbs to run,[1126] Correct old Time,[1127] and regulate the sun;[1128] Go, soar with Plato to th' empyreal sphere, To the first good, first perfect, and first fair;[1129] Or tread the mazy round his follow'rs trod; 25 And quitting sense call imitating God;[1130] As eastern priests in giddy circles run,[1131] And turn their heads to imitate the sun.[1132] Go, teach Eternal Wisdom how to rule[1133]-- Then drop into thyself, and be a fool! 30 Superior beings, when of late they saw A mortal man[1134] unfold all nature's law, Admired such wisdom in an earthly shape,[1135] And showed a Newton, as we show an ape.[1136] Could he, whose rules the rapid comet[1137] bind,[1138] 35 Describe or fix one movement of his mind?[1139] Who saw its fires here rise, and there descend,[1140] Explain his own beginning or his end?[1141] Alas! what wonder![1142] man's superior part[1143] Unchecked may rise, and climb from art to art;[1144] 40 But when his own great work is but begun, What reason weaves, by passion is undone,[1145] Trace science then, with modesty thy guide; First strip off all her equipage of pride; Deduct what is but vanity or dress, 45 Or learning's luxury, or idleness; Or tricks to show the stretch of human brain, Mere curious pleasure, or ingenious pain; Expunge the whole, or lop th' excrescent parts Of all[1146] our vices have created arts; 50 Then see how little the remaining sum, Which served the past, and must the times to come![1147] [Sidenote: The two principles of man, self-love and reason, both necessary.]