The Notebooks of Leonardo da Vinci

in this work of mine the wonderful works of Nature, if you think it would be a criminal thing to destroy it, reflect how much more criminal it is to take the life of a man; and if this, his external form, appears to thee marvellously constructed, remember that it is nothing as compared with the soul that dwells in that structure; for that indeed, be it what it may, is a thing divine. Leave it then to dwell in His work at His good will and pleasure, and let not your rage or malice destroy a life—for indeed, he who does not value it, does not himself deserve it [Footnote 19: In MS. II 15a is the note: chi no stima la vita, non la merita.]. [Footnote: This text is on the back of the drawings reproduced on Pl. CVII. Compare No. 798, 35 note on p. 111: Compare also No. 837 and 838.] 1141. The soul can never be corrupted with the corruption of the body,, but is in the body as it were the air which causes the sound of the organ, where when a pipe bursts, the wind would cease to have any good effect. [Footnote: Compare No. 845.] 1142. The part always has a tendency to reunite with its whole in order to escape from its imperfection. The spirit desires to remain with its body, because, without the organic instruments of that body, it can neither act, nor feel anything. 1143. If any one wishes to see how the soul dwells in its body, let him observe how this body uses its daily habitation; that is to say, if this is devoid of order and confused, the body will be kept in disorder and confusion by its soul. 1144. Why does the eye see a thing more clearly in dreams than with the imagination being awake? 1145. The senses are of the earth; Reason, stands apart in contemplation. [Footnote: Compare No. 842.] 1146. Every action needs to be prompted by a motive. To know and to will are two operations of the human mind. Discerning, judging, deliberating are acts of the human mind. 1147. All our knowledge has its origin in our preceptions. Science, its principles and rules (1148—1161) 1148. Science is the observation of things possible, whether present or past; prescience is the knowledge of things which may come to pass, though but slowly. 1149. Experience, the interpreter between formative nature and the human race, teaches how that nature acts among mortals; and being constrained by necessity cannot act otherwise than as reason, which is its helm, requires her to act. 1150. Wisdom is the daughter of experience. 1151. Nature is full of infinite causes that have never occured in experience. 1152. Truth was the only daughter of Time. 1153. Experience never errs; it is only your judgments that err by promising themselves effects such as are not caused by your experiments. Experience does not err; only your judgments err by expecting from her what is not in her power. Men wrongly complain of Experience; with great abuse they accuse her of leading them astray but they set Experience aside, turning from it with complaints as to our ignorance causing us to be carried away by vain and foolish desires to promise ourselves, in her name, things that are not in her power; saying that she is fallacious. Men are unjust in complaining of innocent Experience, constantly accusing her of error and of false evidence. 1154. Instrumental or mechanical science is of all the noblest and the most useful, seeing that by means of this all animated bodies that have movement perform all their actions; and these movements are based on the centre of gravity which is placed in the middle dividing unequal weights, and it has dearth and wealth of muscles and also lever and counterlever. 1155. OF MECHANICS. Mechanics are the Paradise of mathematical science, because here we come to the fruits of mathematics. [Footnote: Compare No. 660, 11. 19—22 (Vol. I., p. 332). 1156. Every instrument requires to be made by experience. 1157. The man who blames the supreme certainty of mathematics feeds on confusion, and can never silence the contradictions of sophistical sciences which lead to an eternal quackery. 1158. There is no certainty in sciences where one of the mathematical sciences cannot be applied, or which are not in relation with these mathematics. **** TEXT BEYOND THIS POINT STILL NEEDS SOME CLEANUP **** 1159. Any one who in discussion relies upon authority uses, not his understanding, but rather his memory. Good culture is born of a good disposition; and since the cause is more to be praised than the effect, I will rather praise a good disposition without culture, than good culture without the disposition. 1160. Science is the captain, and practice the soldiers. 1161. OF THE ERRORS OF THOSE WHO DEPEND ON PRACTICE WITHOUT SCIENCE. Those who fall in love with practice without science are like a sailor who enters a ship without a helm or a compass, and who never can be certain whither he is going. II. MORALS. What is life? (1162. 1163). 1162. Now you see that the hope and the desire of returning home and to one's former state is like the moth to the light, and that the man who with constant longing awaits with joy each new spring time, each new summer, each new month and new year—deeming that the things he longs for are ever too late in coming—does not perceive that he is longing for his own destruction. But this desire is the very quintessence, the spirit of the elements, which finding itself imprisoned with the soul is ever longing to return from the human body to its giver. And you must know that this same longing is that quintessence, inseparable from nature, and that man is the image of the world. 1163. O Time! consumer of all things; O envious age! thou dost destroy all things and devour all things with the relentless teeth of years, little by little in a slow death. Helen, when she looked in her mirror, seeing the withered wrinkles made in her face by old age, wept and wondered why she had twice been carried away. O Time! consumer of all things, and O envious age! by which all things are all devoured. Death. 1164. Every evil leaves behind a grief in our memory, except the supreme evil, that is death, which destroys this memory together with life. How to spend life (1165-1170). 1165. 0 sleepers! what a thing is slumber! Sleep resembles death. Ah, why then dost thou not work in such wise as that after death thou mayst retain a resemblance to perfect life, when, during life, thou art in sleep so like to the hapless dead? [Footnote: Compare No. 676, Vol. I. p. 353.] 1166. One pushes down the other. By these square-blocks are meant the life and the studies of men. 1167. The knowledge of past times and of the places on the earth is both an ornament and nutriment to the human mind. 1168. To lie is so vile, that even if it were in speaking well of godly things it would take off something from God's grace; and Truth is so excellent, that if it praises but small things they become noble. Beyond a doubt truth bears the same relation to falsehood as light to darkness; and this truth is in itself so excellent that, even when it dwells on humble and lowly matters, it is still infinitely above uncertainty and lies, disguised in high and lofty discourses; because in our minds, even if lying should be their fifth element, this does not prevent that the truth of things is the chief nutriment of superior intellects, though not of wandering wits. But you who live in dreams are better pleased by the sophistical reasons and frauds of wits in great and uncertain things, than by those reasons which are certain and natural and not so far above us. 1169. Avoid studies of which the result dies with the worker. 1170. Men are in error when they lament the flight of time, accusing it of being too swift, and not perceiving that it is sufficient as it passes; but good memory, with which nature has endowed us, causes things long past to seem present. 1171. Learning acquired in youth arrests the evil of old age; and if you understand that old age has wisdom for its food, you will so conduct yourself in youth that your old age will not lack for nourishment. 1172. The acquisition of any knowledge is always of use to the intellect, because it may thus drive out useless things and retain the good. For nothing can be loved or hated unless it is first known. 1173. As a day well spent procures a happy sleep, so a life well employed procures a happy death. 1174. The water you touch in a river is the last of that which has passed, and the first of that which is coming. Thus it is with time present. Life if well spent, is long. 1175. Just as food eaten without caring for it is turned into loathsome nourishment, so study without a taste for it spoils memory, by retaining nothing which it has taken in. 1176. Just as eating against one's will is injurious to health, so study without a liking for it spoils the memory, and it retains nothing it takes in. 1177. On Mount Etna the words freeze in your mouth and you may make ice of them. [Footnote 2: There is no clue to explain this strange sentence.] Just as iron rusts unless it is used, and water putrifies or, in cold, turns to ice, so our intellect spoils unless it is kept in use. You do ill if you praise, and still worse if you reprove in a matter you do not understand. When Fortune comes, seize her in front with a sure hand, because behind she is bald. 1178. It seems to me that men of coarse and clumsy habits and of small knowledge do not deserve such fine instruments nor so great a variety of natural mechanism as men of speculation and of great knowledge; but merely a sack in which their food may be stowed and whence it may issue, since they cannot be judged to be any thing else than vehicles for food; for it seems to me they have nothing about them of the human species but the voice and the figure, and for all the rest are much below beasts. 1179. Some there are who are nothing else than a passage for food and augmentors of excrement and fillers of privies, because through them no other things in the world, nor any good effects are produced, since nothing but full privies results from them. On foolishness and ignorance (1180—1182). 1180. The greatest deception men suffer is from their own opinions. 1181. Folly is the shield of shame, as unreadiness is that of poverty glorified. 1182. Blind ignorance misleads us thus and delights with the results of lascivious joys. Because it does not know the true light. Because it does not know what is the true light. Vain splendour takes from us the power of being …. behold! for its vain splendour we go into the fire, thus blind ignorance does mislead us. That is, blind ignorance so misleads us that … O! wretched mortals, open your eyes. On riches (1183—1187). 1183. That is not riches, which may be lost; virtue is our true good and the true reward of its possessor. That cannot be lost; that never deserts us, but when life leaves us. As to property and external riches, hold them with trembling; they often leave their possessor in contempt, and mocked at for having lost them. 1184. Every man wishes to make money to give it to the doctors, destroyers of life; they then ought to be rich. [Footnote 2: Compare No. 856.] Man has much power of discourse which for the most part is vain and false; animals have but little, but it is useful and true, and a small truth is better than a great lie. 1185. He who possesses most must be most afraid of loss. 1186. He who wishes to be rich in a day will be hanged in a year. 1187. That man is