It is inconceivable that inanimate brute matter should, without the mediation of something else which is not material, operate upon and affect other matter without mutual contact, as it must be, if gravitation in the sense of Epicurus, be essential and inherent in it. And this is one reason why I desired you would not ascribe innate gravity to me. That gravity should be innate, inherent, and essential to matter, so that one body may act upon another at a distance through a vacuum, without the mediation of anything else, by and through which their action and force may be conveyed from one to another, is to me so great an absurdity that I believe no man who has in philosophical matters a competent faculty of thinking can ever fall into it. Gravity must be caused by an agent acting constantly according to certain laws; but whether this agent be material or immaterial, I have left open to the consideration of my readers.

I keep the subject constantly before me, and wait 'till the first dawnings open slowly, by little and little, into a full and clear light.

One [method] is by a Watch to keep time exactly. But, by reason of the motion of the Ship, the Variation of Heat and Cold, Wet and Dry, and the Difference of Gravity in different Latitudes, such a watch hath not yet been made.

A good watch may serve to keep a recconing at Sea for some days and to know the time of a Celestial Observ[at]ion: and for this end a good Jewel watch may suffice till a better sort of Watch can be found out. But when the Longitude at sea is once lost, it cannot be found again by any watch.

Whereas in Arithmetick Questions are only resolv'd by proceeding from given Quantities to the Quantities sought, Algebra proceeds in a retrograde Order, from the Quantities sought as if they were given, to the Quantities given as if they were sought, to the End that we may some Way or other come to a Conclusion or Æquation, from which one may bring out the Quantity sought. And after this Way the most difficult problems are resolv'd, the Resolutions whereof would be sought in vain from only common Arithmetick. Yet Arithmetick in all its Operations is so subservient to Algebra, as that they seem both but to make one perfect Science of Computing; and therefore I will explain them both together.

Atheism is so senseless. When I look at the solar system, I see the earth at the right distance from the sun to receive the proper amounts of heat and light. This did not happen by chance.

Tact is the knack of making a point without making an enemy.

Les hommes construisent trop de murs et pas assez de ponts.

Newton and Locke are examples of the deep sagacity which may be acquired by long habits of thinking and study.

According to Sir Isaac Newton's Calculations, the last Comet that made its Appearance in 1680, imbib'd so much Heat by its Approaches to the Sun, that it would have been two thousand times hotter than red hot Iron, had it been a Globe of that Metal; and that supposing it as big as the Earth, and at the same Distance from the Sun, it would be fifty thousand Years in cooling, before it recovered its natural Temper. In the like manner, if an Englishman considers the great Ferment into which our Political World is thrown at present, and how intensely it is heated in all its Parts, he cannot suppose that it will cool again in less than three hundred Years. In such a Tract of Time it is possible that the Heats of the present Age may be extinguished, and our several Classes of great Men represented under their proper Characters. Some eminent Historian may then probably arise that will not write recentibus odiis (as Tacitus expresses it) with the Passions and Prejudices of a contemporary Author, but make an impartial Distribution of Fame among the Great Men of the present Age.

The greatest scientist who ever lived was Isaac Newton...[about Principia Mathematica] By all odds it's the greatest scientific book ever written or ever will be written, I think.

Newton's own motto, "hypotheses non fingo" was, in a sense, disregarded by Newton himself: he rejected hypotheses only where they violated his own "regula philosophandi", that is to say, his principle of their strict parsimony. In terms of present-day methodology, we reject hypotheses as scientifically meaningless if they are incapable even of indirect test; and we reject them as superfluous or as implausible if they are too complex and artificial to conform with well established canons of inductive probability. But freedom of scientific theorizing must be preserved wherever the conditions of meaningfulness and of economy appear to be satisfied.

Kepler succeeded in showing that the planets move along elliptic paths and that the sun lies at a focus of each of these s... Each planet moves so that a straight line drawn to connect it with the sun sweeps out equal areas in equal times. ...The discoveries ...enabled Newton to formulate the laws of mechanics in general and those of gravitation in particular. ...He was able to develop Kepler's laws into a comprehensive physical theory only because he managed first to create the necessary mathematical tools... differential and integral calculus, the basic mathematical techniques for dealing with variable quantities, such as the movement of bodies in the course of time. ...[H]e succeeded in drawing from Kepler's empirical laws the principles of motion that applied [to] every instant of time and thus shaped planetary motion into complete orbits.

Now I a fourfold vision see,And a fourfold vision is given to me ;'Tis fourfold in my supreme delight,And threefold in soft Beulah's night,And twofold Always. May God us keepFrom Single vision, & Newton's sleep !

No monument should stand over [my] grave, only an apple-tree, in memory of the three apples; the two of Eve and Paris, which made hell out of earth, and that of Newton, which elevated the earth again into the circle of heavenly bodies.

The landscape has been so totally changed, the ways of thinking have been so deeply affected, that it is very hard to get hold of what it was like before... It is very hard to realize how total a change in outlook he has produced.

If I had stayed for other people to make my tools and things for me, I had never made anything.

I can calculate the motions of the heavenly bodies, but not the madness of the people.

The Antients, as we learn from Pappus, in vain endeavour'd at the Trisection of an Angle, and the finding out of two mean Proportionals by a right line and a Circle. Afterwards they began to consider the Properties of several other Lines. as the Conchoid, the Cissoid, and the Conick Sections, and by some of these to solve these Problems. At length, having more throughly examin'd the Matter, and the Conick Sections being receiv'd into Geometry, they distinguish'd Problems into three Kinds: viz. (1.) Into Plane ones, which deriving their Original from Lines on a Plane, may be solv'd by a right Line and a Circle; (2.) Into Solid ones, which were solved by Lines deriving their Original from the Consideration of a Solid, that is, of a Cone; (3.) And Linear ones, to the Solution of which were requir'd Lines more compounded. And according to this Distinction, we are not to solve solid Problems by other Lines than the Conick Sections; especially if no other Lines but right ones, a Circle, and the Conick Sections, must be receiv'd into Geometry. But the Moderns advancing yet much farther, have receiv'd into Geometry all Lines that can be express'd by Æquations, and have distinguish'd, according to the Dimensions of the Æquations, those Lines into Kinds; and have made it a Law, that you are not to construct a Problem by a Line of a superior Kind, that may be constructed by one of an inferior one. In the Contemplation of Lines, and finding out their Properties, I like their Distinction of them into Kinds, according to the Dimensions thy Æquations by which they are defin'd. But it is not the Æquation, but the Description that makes the Curve to be a Geometrical one.

After the same Manner in Geometry, if a Line drawn any certain Way be reckon'd for Affirmative, then a Line drawn the contrary Way may be taken for Negative: As if AB be drawn to the right, and BC to the left; and AB be reckon'd Affirmative, then BC will be Negative; because in the drawing it diminishes AB...

The Circle is a Geometrical Line, not because it may be express'd by an Æquation, but because its Description is a Postulate. It is not the Simplicity of the Æquation, but the Easiness of the Description, which is to determine the Choice of our Lines for the Construction of Problems. For the Æquation that expresses a Parabola, is more simple than That that expresses a Circle, and yet the Circle, by reason of its more simple Construction, is admitted before it. The Circle and the Conick Sections, if you regard the Dimension of the Æquations, are of the fame Order, and yet the Circle is not number'd with them in the Construction of Problems, but by reason of its simple Description, is depressed to a lower Order, viz. that of a right Line; so that it is not improper to express that by a Circle that may be expressed by a right Line. But it is a Fault to construct that by the Conick Sections which may be constructed by a Circle. Either therefore you must take your Law and Rule from the Dimensions of Æquations as observ'd in a Circle, and so take away the Distinction between Plane and Solid Problems; or else you must grant, that that Law is not so strictly to be observ'd in Lines of superior Kinds, but that some, by reason of their more simple Description, may be preferr'd to others of the same Order, and may be number'd with Lines of inferior Orders in the Construction of Problems.

In Constructions that are equally Geometrical, the most simple are always to be preferr'd. This Law is so universal as to be without Exception. But Algebraick Expressions add nothing to the Simplicity of the Construction; the bare Descriptions of the Lines only are here to be consider'd and these alone were consider'd by those Geometricians who joyn'd a Circle with a right Line. And as these are easy or hard, the Construction becomes easy or hard: And therefore it is foreign to the Nature of the Thing, from any Thing else to establish Laws about Constructions. Either therefore let us, with the Antients, exclude all Lines besides the Circle, and perhaps the Conick Sections, out of Geometry, or admit all, according to the Simplicity of the Description. If the Trochoid were admitted into Geometry, we might, by its Means, divide an Angle in any given Ratio. Would you therefore blame those who should make Use of this Line... and contend that this Line was not defin'd by an Æquition, but that you must make use of such Lines as are defin'd by Æquations?

Geometry was invented that we might expeditiously avoid, by drawing Lines, the Tediousness of Computation. Therefore these two Sciences ought not to be confounded. The Antients did so industriously distinguish them from one another, that they never introduc'd Arithmetical Terms into Geometry. And the Moderns, by confounding both, have lost the Simplicity in which all the Elegancy of Geometry consists. Wherefore that is Arithmetically more simple which is determin'd by the more simple Æquations, but that is Geometrically more simple which is determin'd by the more simple drawing of Lines; and in Geometry, that ought to be reckon'd best which is Geometrically most simple. Wherefore, I ought not to be blamed, if with that Prince of Mathematicians, Archimedes and other Antients, I make use of the Conchoid for the Construction of solid Problems.

Geometrical Speculations have just as much Elegancy as Simplicity, and deserve just so much praise as they can promise Use.

Useful Things, though Mechanical, are justly preferable to useless Speculations in Geometry, as we learn from Pappus.

In my Judgment no Lines ought to be admitted into plain Geometry besides the right Line and the Circle.

The Ellipse is the most simple of the Conic Sections, most known, and nearest of Kin to a Circle, and easiest describ'd by the Hand in plano. Though many prefer the Parabola before it, for the Simplicity of the Æquation by which it is express'd. But by this Reason the Parabola ought to be preferr'd before the Circle it self, which it never is. Therefore the reasoning from the Simplicity of the Æquation will not hold. The modern Geometers are too fond of the Speculation of Æquations.

The Simplicity of Figures depend upon the Simplicity of their Genesis and Ideas, and an Æquation is nothing else than a Description (either Geometrical or Mechanical) by which a Figure is generated and rendered more easy to the Conception.

Through algebra you easily arrive at equations, but always to pass therefrom to the elegant constructions and demonstrations which usually result by means of the method of porisms is not so easy, nor is one's ingenuity and power of invention so greatly exercised and refined in this analysis.

In default of any other proof, the thumb would convince me of the existence of a God.

It is the perfection of God's works that they are all done with the greatest simplicity. He is the God of order and not of confusion. And therefore as they would understand the frame of the world must endeavor to reduce their knowledge to all possible simplicity, so must it be in seeking to understand these visions.

Truth is ever to be found in simplicity, and not in the multiplicity and confusion of things.

God created everything by number, weight and measure.

Every body continues in its state of rest, or of uniform motion in a right line, unless it is compelled to change that state by forces impressed upon it.

I do not know what I may appear to the world, but to myself I seem to have been only like a boy playing on the sea-shore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.

I have studied these things - you have not.

To explain all nature is too difficult a task for any one man or even for any one age. 'Tis much better to do a little with certainty, & leave the rest for others that come after you, than to explain all things by conjecture without making sure of any thing.

It seems to me, that if the matter of our sun and planets and all the matter of the universe, were evenly scattered throughout all the heavens, and every particle had an innate gravity towards all the rest, and the whole of space throughout which this matter was scattered was but finite, the matter on [toward] the outside of this space would, by its gravity, tend towards all the matter on the inside, and, by consequence, fall down into the middle of the whole space, and there compose one great spherical mass. But if the matter was evenly disposed throughout an infinite space it could never convene into one mass; but some of it would convene into one mass and some into another, so as to make an infinite number of great masses, scattered at great distances from one another throughout all that infinite space.

1. Fidelity & Allegiance sworn to the King is only such a fidelity and obedience as is due to him by the law of the land; for were that faith and allegiance more than what the law requires, we would swear ourselves slaves, and the King absolute; whereas, by the law, we are free men, notwithstanding those Oaths. 2. When, therefore, the obligation by the law to fidelity and allegiance ceases, that by the Oath also ceases...

Bullialdus wrote that all force respecting the Sun as its center & depending on matter must be reciprocally in a duplicate ratio of the distance from the center.

I have not been able to discover the cause of those properties of gravity from phenomena, and I frame no hypotheses; for whatever is not deduced from the phenomena is to be called a hypothesis, and hypotheses, whether metaphysical or physical, whether of occult qualities or mechanical, have no place in experimental philosophy.

Our design, not respecting arts, but philosophy, and our subject, not manual, but natural powers, we consider chiefly those things which relate to gravity, levity, elastic force, the resistance of fluids, and the like forces, whether attractive or impulsive; and therefore we offer this work as mathematical principles of philosophy; for all the difficulty of philosophy seems to consist in this - from the phenomena of motions to investigate the forces of nature, and then from these forces to demonstrate the other phenomena...

I wish we could derive the rest of the phenomena of nature by the same kind of reasoning from mechanical principles; for I am induced by many reasons to suspect that they may all depend upon certain forces by which the particles of bodies, by some causes hitherto unknown, are either mutually impelled towards each other, and cohere in regular figures, or are repelled and recede from each other; which forces being unknown, philosophers have hitherto attempted the search of nature in vain; but I hope the principles here laid down will afford some light either to that or some truer method of philosophy.

Rational mechanics must be the science of the motions which result from any forces, and of the forces which are required for any motions, accurately propounded and demonstrated. For many things induce me to suspect, that all natural phenomena may depend upon some forces by which the particles of bodies are either drawn towards each other, and cohere, or repel and recede from each other: and these forces being hitherto unknown, philosophers have pursued their researches in vain. And I hope that the principles expounded in this work will afford some light, either to this mode of philosophizing, or to some mode which is more true.

I can calculate the motions of erratic bodies, but not the madness of a multitude.

When a man is taken in a mystical sense, his qualities are often signified by his actions, and by the circumstances of things about him. So a Ruler is signified by his riding on a beast; a Warrior and Conqueror, by his having a sword and bow; a potent man, by his gigantic stature; a Judge, by weights and measures... the affliction or persecution which a people suffers in laboring to bring forth a new kingdom, by the pain of a woman in labor to bring forth a man-child; the dissolution of a body politic or ecclesiastic, by the death of a man or beast; and the revival of a dissolved dominion, by the resurrection of the dead.

Yet sometimes vegetables and animals are, by certain epithets or circumstances, extended to other significations; as a Tree, when called the tree of life or of knowledge; and a Beast, when called the old serpent, or worshiped. When a Beast or Man is put for a kingdom, his parts and qualities are put for the analogous parts and qualities of the kingdom; as the head of a Beast, for the great men who precede and govern; the tail for the inferior people, who follow and are governed; the heads, if more than one, for the number of capital parts, or dynasties, or dominions in the kingdom, whether collateral or successive, with respect to the civil government; the horns on any head, for the number of kingdoms in that head, with respect to military power...

The other part of the true religion is our duty to man. We must love our neighbour as our selves, we must be charitable to all men for charity is the greatest of graces, greater then even faith or hope & covers a multitude of sins. We must be righteous & do to all men as we would they should do to us.

Idolatry is a more dangerous crime because it is apt by the authority of Kings & under very specious pretenses to insinuate it self into mankind. Kings being apt to enjoyn the honour of their dead ancestors: & it seeming very plausible to honour the souls of Heroes & Saints & to believe that they can heare us & help us & are mediators between God & man & reside & act principally in the temples & statues dedicated to their honour & memory? And yet this being against the principal part of religion is in scripture condemned & detested above all other crimes. The sin consists first in omitting the service of the true God.

But it is not to be conceived that mere mechanical causes could give birth to so many regular motions: since the Comets range over all parts of the heavens, in very eccentric orbits. For by that kind of motion they pass easily through the orbs of the Planets, and with great rapidity; and in their aphelions, where they move the slowest, and are detain'd the longest, they recede to the greatest distances from each other, and thence suffer the least disturbance from their mutual attractions.