Notebooks

by Leonardo da Vinci

For I know that there are numberless people who, in order to gratify one of their appetites, would destroy God and the whole of the universe.

It is impossible that anything of itself alone can be the cause of its creation; and those things which are of themselves are eternal.

Leonardo had grown up with this conception based on ancient traditions and accepted it on the whole; and as he was self-educated it is at times difficult to discern whether certain of his notes expressed original ideas or were transcriptions from books procured during his self-education. In explaining phenomena, however, he did not refer to hypothetical unknown agencies but to the activities of nature. While agreeing with some established theories he rejected others by his strictly empirical and experimental method.

Everything comes from everything, and everything is made from everything, and everything can be turned into everything else; because that which exists in the elements is composed of those elements.

Let me begin by setting forth certain conceptions and conclusions. That thing is higher which is more remote from the centre of the world, and that is lower which is nearer to the centre. Water does not move of itself unless it descends and in moving it descends. These four conceptions, linked two by two, serve to prove that water that does not move of itself has its surface equidistant to the centre of the world, speaking of the great masses and not of drops or other small quantities that attract one another as the steel its filings.

It’s interesting to read this after having studied Physics. What isn’t though? This is how Leonardo thought of gravity.

Water held a great fascination for Leonardo. He looked upon it as the driving force of the universe and thought that he might solve the mysteries of creation by studying the laws of its movement through earth and air.

The existence of marine shells and fossils inland and at high altitudes and the varying strata of soil or rock led him to conceive of streams as chief agents in the formation of the earth’s surface, and he foreshadowed the conception of gradual evolution.

Water is the driver of nature. Water, which is the vital humour of the terrestrial machine, moves by its own natural heat.

Whether the flow and ebb are caused by the moon or sun or are the breaking of this machine of the earth. How the flow and ebb differ in different countries. How in the end the mountains will be levelled by the waters, seeing that they wash away the earth which covers them and uncover their rocks, which begin to crumble and subdued alike by heat and frost are being continually changed into soil. The waters wear away their bases and the mountains fall bit by bit in ruin into the rivers … and by reason of this ruin the waters rise in a swirling flood and form great seas.

And no part of the earth is so high but that the sea has been at its foundations, and no depth of the sea is so low but that the highest mountains have their bases there. And so it is now sharp and now strong, now acid and now bitter, now sweet and now thick or thin, now it is seen bringing damage or pestilence and then health or, again, poison. So one might say that it changes into as many natures as are the different places through which it passes. And as the mirror changes with the colour of its objects so this changes with the nature of the place where it passes: health-giving, harmful, laxative, astringent, sulphurous, salt, sanguine, depressed, raging, angry, red, yellow, green, black, blue, oily, thick, thin.

Only in high seas do the waves advance without recoil. In small ponds one and the same stroke gives birth to many motions of advance and recoil. The greater wave is covered with innumerable other waves which move in different directions; and these are deep or shallow according to the power that generated them. … Many waves turned in different directions can be created between the surface and the bottom of the same body of water at the same time … all the impressions caused by things striking upon the water can penetrate one another without being destroyed. One wave never penetrates another; but they only recoil from the spot where they strike.

The movement of these things towards the shore commences when the percussion of the falling wave meets the reflex wave, for the things raised from the bottom often leap up in the wave that bounds towards the shore, and their solid bodies are raised in the mound which then draws them back towards the sea; and so continues the succession until the storm begins to abate, and they are left stage by stage where the greater waves had reached and deposited the booty which they carried, and the succeeding waves did not reach the same mark. There remain the things cast up by the sea.

If a drop of water falls into the sea when it is calm, it must of necessity follow that the whole surface of the sea is raised imperceptibly, seeing that water cannot be compressed within itself like air.

The creature that resides within the shell constructs its dwelling with joints and seams and roofing and various other parts, just as man does in the house where he dwells; and this creature expands the house and roof gradually as its body increases, since it is attached to the sides of these shells. Therefore the brightness and smoothness of these shells on the inner side is somewhat dulled at the point where they are attached to the creature that dwells there, and its hollow is roughened, in order to receive the knitting together of the muscles by means of which the creature draws itself in when it wishes to shut itself up within its house.

And we find oysters together in very large families, among which some may be seen with their shells still joined together, indicating that they were left there by the sea and that they were still living when the strait of Gibraltar was cut through.

Here a doubt arises, and that is: whether the Flood which came at the time of Noah was universal or not. And it would seem not, for the reasons which will now be given: We have it in the Bible that the said Flood consisted in forty days and forty nights of continuous and universal rain, and that this rain rose ten cubits above the highest mountain in the world. But if it had been the case that the rain was universal it would have formed a covering around the globe spherical in shape. And this spherical surface is in every part equidistant from the centre of its sphere; and the waters of the sphere finding themselves in the aforesaid condition it is impossible for the water upon the surface to move; because water does not move of its own accord unless to descend. How then did the water of so great a flood depart, if it is proved that it had no power of motion? and if it departed, how did it move unless it went upwards? Here, then, natural reasons fail us; and therefore to resolve such a doubt we must needs either call in a miracle to aid us, or else say that all this water was evaporated by the heat of the sun.

Well, now we know these were fantastic stories and translate them symbolically.

A river that flows from the mountains deposits a great quantity of large stones in its bed, and these stones still retain some part of their angles and sides; and as it proceeds on its course it carries down with it lesser stones with the angles more worn away, and so the large stones make smaller ones; and further on it deposits first coarse and then fine gravel, and after this follows sand at first coarse and then more fine; and thus continuing the water turbid with sand and shingle reaches the sea.

All the outlets of the water flowing from the mountain to the sea carry stones from the mountain with them to the sea; and by the backwash of the sea water against the mountains, these stones were thrown back towards the mountain; and as the waters moved towards the sea and returned from it the stones turned with them and as they rolled their corners struck together; and as the parts of least resistance to the blows were worn away, the stones ceased to be angular and became round in form, as may be seen on the shores of Elba.

The first and most essential thing is stability. As to the foundations of the component parts of temples and other public buildings, their depths should bear the same relation one to another, as do the weights which are to rest upon them. Every part of the depth of the earth in a given space is composed of layers, and each layer is composed of heavier and lighter parts; the lowest being the heaviest.

It is not denied that the Nile is always turbid as it enters the Egyptian Sea and that this turbidness is caused by the soil that this river carries away continually from the places through which it passes; which soil never returns back, nor does the sea receive it except it throws it on its shores. Behold the ocean of sand beyond Mount Atlas where it was once covered with salt water.

Although the voices which penetrate the air proceed from their sources in circular motion, nevertheless the circles which are propelled from their different centres meet without any hindrance and penetrate and pass across one another keeping to the centre from which they spring.

The organic and inorganic worlds are both of similar nature and subject to the same natural laws. Man is a part of a world, a microcosm included in a macrocosm.

Man has been called by the ancients a lesser world and indeed the term is well applied. Seeing that if a man is composed of earth, water, air, and fire, this body of earth is similar. While man has within himself bones as a stay and framework for the flesh, the world has stones which are the supports of earth.

Of Spirits We have said that the definition of a spirit is a power united to a body, because of itself it can neither rise nor take any kind of movement in space, and if you say that it does rise of itself this cannot be within the elements. For if the spirit is an incorporeal quantity, this quantity is called a vacuum, and the vacuum does not exist in nature; and granting that one were formed it would be immediately filled up by the rushing in of the element in which such a vacuum had been generated.

One sees that a part of water has neither gravity nor levity when merged in the other water, but will acquire weight if drawn up into the air; and if you were to draw the air beneath the water, then the water on finding itself above this air acquires weight, which weight it cannot support by itself, and hence its collapse is inevitable; and it will fall into the water at the spot where there is a vacuum. The same thing would happen to a spirit if it were amid the elements where it would continually generate a vacuum in whatever element it might find itself and for this reason it would be continually flying towards the sky until it had quitted those elements.

This is interesting to read considering that water exhibits the same behavior as other forms of matter when on earth because of gravity. If water is above anything that’s less dense than it, it subsumes it, so by that logic… the spirit analogy is a little off because spirit is not matter so can’t be understood in the context of matter. It’s like a proxy for explaining our consciousness.

The voice is movement of air in friction against a dense body, or of a dense body in friction against the air—which is the same thing; and this friction of the dense with the rare condenses the rare and causes resistance; moreover the rare when in swift motion, and the rare moving slowly condense each other at their contact, and make a noise or great uproar; and the sound or murmur caused by one rare moving through another rare at a moderate speed is like a great flame which creates noises in the air.

Therefore we may say that the spirit cannot produce a voice without movement of the air, in it there is none and it cannot emit what it has not; and if it desires to move the air in which it is diffused it becomes necessary that the spirit should multiply itself, and that cannot multiply which has no quantity.

There can be no voice where there is no motion or percussion of the air; there can be no percussion of the air where there is no instrument; there can be no instrument without a body; this being so a spirit can have neither voice, nor form, nor force; and if it were to assume a body it could not penetrate nor enter where the doors are closed. And if any should say that through air collected together and compressed a spirit may assume bodies of various forms, and by such instrument may speak and move with force—to him I reply that where there are neither nerves nor bones there can be no force exerted in any movement made by imaginary spirits.

In order to see the nature of the planets, open the roof and note at the base one planet singly: the reflected movement on this base will show the nature of this planet; but arrange that the base reflects only one at a time.65 Construct glasses in order to see the moon large.

Of the eye. Of bodies less than the pupil of the eye that which is nearest to it will be least discerned by the eye. And from this experience it is made known to us that the power of sight is not reduced to a point. … But the images of the objects conveyed to the pupil of the eye are distributed on this pupil exactly as they are distributed in the air: and the proof of this is shown to us when we look at the starry sky without sighting more fixedly one star than another; the sky then appears all strewn with stars; and their proportions in the eye are the same as in the sky and likewise the spaces between them.

Nothing light remains among less light things. Whether the moon has its seat within its elements or not. And if the moon has not its special seat like the earth in the midst of its elements, how is it that it does not fall in the midst of our elements? And if it is not in the midst of its elements and does not fall down, it must be lighter than all other elements. And if it is lighter than all other elements why is it solid and not transparent?

The sun has substance, shape, motion, radiance, heat, and generative power: and these qualities all emanate from it without its diminution.

All vital force descends from it since the heat that is in living creatures comes from the soul (vital spark); and there is no other heat nor light in the universe. … And certainly those who have chosen to worship men as gods such as Jove, Saturn, Mars, and the like have made a very great error, seeing that even if a man were as large as our earth he would seem like one of the least of the stars which appears but a speck in the universe; and seeing also that men are mortal and subject to decay and corruption in their tombs.

This is usually not intentional. What people worship when they worship other people is the image of what they consider an internal ideal which they cannot reach. People who desire power then shape their image to fit an ideal that other people want to worship. An example is Christ, the personification of goodness in Christianity. In religion, this image is also a symbol for community. By virtue of worshiping the image of Christ, we are, collectively. In maturity, they see this for what it is and move on with life, revering the person that they look up to. In other situations, they worship them for favors from the person or the community, a viable approach to achieving success. In the worst case, they get stuck worshiping the ideal through needless ritual, seeing the achievements as supernatural or worse still, love (amor) for the image. Of all the things that can consume a person’s soul, speaking of metaphysics, amor and eros are the worst but also the most potent.

The Spera and Marullo and many others praise the sun.*

The sun is symbolic for potent energy which it proves everyday through its impact on earth.

Heat and cold proceed from the nearness or remoteness of the sun. Heat and cold cause the movement of the elements. No element has of itself weight or lightness…. The motion originates from the fact that what is thinner can neither resist nor support what is more dense. Lightness is born of weight and weight of lightness; and they give birth one to another at the same time; repaying in the same instant the boon of their creation they grow in power as they grow in life, and have more life as they have more motion; and they destroy one another in the same instant in the common vendetta of their death.

And so it is with the elements. If for instance a quantity of air lay beneath water, the water would immediately acquire weight; not because it has itself changed, but because it does not meet with the due amount of resistance; it therefore descends into the position occupied by the air beneath it while the air fills up the vacuum which the weight has left.

No element has weight or lightness unless it moves. The Earth is in contact with the Water and the Air and has of itself neither weight nor lightness. It has no consciousness of the Water and Air that surround it except when they happen to move. And this is shown by the leaves of plants which grow upon the earth in contact with water and air, and which do not bend except to the movement of air and water.

Lightness is an incident created when the thinner element is drawn beneath the less thin … which then acquires weight and meets with insufficient resistance from the thinner element below which then acquires lightness.

Levity and gravity are caused by immediate motion. Motion is created by heat and cold. Motion is an incident created by inequality of weight and force….

Every movement of the elements arises from heat and cold. Gravity and levity are created in the elements.82 Weight comes into being when an element is placed above another element thinner than itself. Weight is caused by one element having been drawn within another.

Every gravity weighs through the central line of the universe because it is drawn to this centre from all parts. A central line of the universe is that which arises from the centre of the world and ends in the centre of gravity of every body.

Force is spiritual essence which by accidental violence is united to weighty bodies, restraining them from following their natural inclination; and here although of short duration it often shows itself of marvellous power.

Force is the product of dearth and profusion. It is the child of material motion and the grandchild of spiritual motion, and the mother and origin of weight. Weight is confined to the elements of water and earth, but force is unlimited; for by it infinite worlds can be set in motion if it were possible to make instruments by which this force could be generated.

Weight and force together with the motion of bodies and percussion are the four powers of nature by which the human race in its marvellous and various works seems to create a second nature in this world; for by the use of such powers all the visible works of mortals have their being and their death.

Force is a spiritual energy, an invisible power which is imparted by violence from without to all bodies that are without their natural balance. Force is nothing but a spiritual energy, an invisible power, which is created and imparted, through violence from without, by animated bodies to inanimate bodies, giving to these the similarity of life, and this life works in a marvellous way, constraining and transforming in place and shape all created things. It speeds in fury to its undoing and continues to modify according to the occasion.

Force is the same throughout and through all the body where it is generated. Force is only a desire of flight. Always it desires to weaken and to spend itself.

Direct movement is that which extends from one point to another by the shortest line. Curved movement is that in which no direct movement is to be found in any part. Spiral movement is composed of an oblique and curved line which is such that the lines drawn from the centre to the circumference are all found to be of various lengths. And it is of four kinds, convex spiral, plane spiral, concave spiral, and the fourth is columnar spiral.

What is the cause of movement. What movement is in itself. What it is which is most adapted for movement. What is impetus; what is the cause of impetus; the medium in which it is created. What is percussion; what is its cause. What is rebound. What is the curve of straight movement and its cause.

A point has no part; a line is the transit of a point; points are the boundaries of a line. An instant has no time. Time is made of movement of the instant, and instants are the boundaries of time.

The movements of weight are of three kinds, of which two are contrary and the third participates in one and the other. The reason is that the movement made from below upwards becomes feebler the more it rises; the other on the contrary grows stronger the further it descends. While the first leaves its highest contact unharmed the second, on the contrary, inflicts great damage to itself and to others; the third movement is transverse and half of it resembles the weight that descends and the other half is like the weight that rises.