Pierre Louis Maupertuis

“ More industrious and sensible philosophers judged only that it would be difficult to understand the principles of motion, and invented reasons to despair of ever knowing them, as an excuse to get out of doing experiments.
A true philosopher does not engage in vain disputes about the nature of motion ”

“ Consider the habits of those who live there, how they lie, steal, and murder; vice is more common than virtue everywhere. Many of those miserable people are despairing, troubled by gout, stones and other diseases that make their life unbearable; almost everyone is vexed by sorrow and disappointments."
Several philosophers seem to have had this perspective and, forgetting all the beauties in the universe, sought to justify God for having created such imperfections. ”

“ Rather, Fermat sought to explain refraction using a totally different and purely metaphysical principle.
Everyone knows that, when light or another body travels from one point to another in a straight line, it follows the path of shortest distance and time. ”

“ Only thus can we gain a fitting idea of the power and wisdom of the supreme Being, not from some small part of creation for which we know neither the construction, usage nor its relationship to other parts. What satisfaction for the human spirit in contemplating these laws of motion and equilibrium for all bodies in the universe, and in finding within them proof of the existence of Him who governs the universe! ”

“ Rather, I consider the arguments of a philosopher who made such grand discoveries that he could well judge the truly marvellous in Nature, and whose reasoning was more precise than that of the others. ”

“ These people then add metaphysical arguments to these arguments. They require that every process in Nature take a certain time, and obey a law of continuity. They object that when a perfectly inelastic body collides with an impassable barrier, its speed must go to zero instantly, without passing through any intermediate values; or its speed instantly is transformed into its opposite, without passing through zero. ”

“ Aside from the question of whether all human beings do indeed believe in God's existence, this argument would be refuted by only a handful of people who thought differently from all other inhabitants of the Earth. ”

“ The motive force (i.e., the ability of a moving body to move other bodies) is just terminology filling in for understanding and has no meaning beyond the results of phenomena. It is only mental habit that prevents us from realizing how miraculous it is that motion can be passed from one body to another. Once our eyes have opened, nothing is so striking. ”

“ Animals without mouths cannot live; those lacking organs of generation cannot reproduce themselves. The few animals that have survived are those with well-ordered parts suited to survival; thus, the animals that we see today are but the smallest part of those produced by a soulless universe.
Almost all of the modern authors that consider physics and natural history merely extend the old arguments of the organization of animals and plants, pushing them into ever finer details of Nature. ”

“ How does it help to wonder at the regularity of the planets, how they rotate in the same direction, in almost the same plane, and in orbits that are almost geometrically similar, if we cannot see why it is better that they move thus and not otherwise? All those poisonous plants and deadly animals are produced and preserved so carefully by Nature -- how can we recognize from them the wisdom and kindness of Him who created them? If we found only such things in Nature, it might well be the work of demons. ”

“ Of those who have applied themselves to studying the Universe, several have found traces of the wisdom and power of Him who governs it. The more the field of physics has progressed, the more arguments we find for His existence. However, some have been confused by the character of the Divinity revealed in Nature, while others, almost religiously zealous, have given too much weight to some arguments, considering them proofs when they were not. ”

“ Finding traces of order and suitability in the construction of animals may lead us to unsettling conclusions. The snake, which neither walks nor flies, could not evade the pursuit of other animals if it had not been blessed with such flexibility that it slithers faster than many animals can walk. ”

“ These arguments are not satisfying, but neither can they be soundly refuted. Still, a true philosopher should neither be dazzled by the order and suitability of the parts of the universe, nor seek to grasp things that lie beyond Nature. Despite the disorder observed in Nature, one finds enough traces of the wisdom and power of its Author that one cannot fail to recognize Him. ”

“ It has to be admitted that these "proofs" have been abused; some give the arguments more weight than they deserve, whereas others multiply them too much. The bodies of animals and plants are machines too sophisticated for our understanding; their smallest parts escape our notice and we are too ignorant of their usage and purpose that we can presume to judge how much wisdom and power went into their construction. ”

“ Truly our perspective is limited to where we are; we cannot see far enough to appreciate the order and interconnectedness of things. If we could, we would undoubtedly find the marks of God's wisdom as well as His intelligence in its execution. ”

“ The more one considers elasticity, the more it seems to require that the elastic body have parts that can move relative to one another under stress.
Hence, it seems more reasonable to assert that the fundamental particles of matter are perfectly hard, rather than to pretend that perfectly hard bodies do not exist in Nature. ”

“ Admittedly, such research is more difficult than studying an insect, a flower, or similar things that Nature offers to our eyes every moment. But we can be aided in our difficult march by a guide, one who is sure-footed although he has not yet gone where we would like to go.
Until now, the goals of mathematics have rarely gone beyond coarse needs of the body and useless speculations of the spirit. ”

“ The truths that it has uncovered are mostly those relating to dimensions and numbers. One should not be deceived by philosophical works that pretend to be mathematical, but are merely dubious and murky metaphysics. ”

“ When two inelastic bodies collide, their parts are inseparable and inflexible; hence, the impact can affect only their speed. The two bodies press and push until the speed of the first equals the speed of the second. After the impact, inelastic bodies move with a common speed. ”

“ What is this power that bodies seem to have to act on one another?
We observe that some particles of matter are in motion, while others are at rest. Hence, motion is not an essential property of matter ”

“ From the all too few ancient geometers who undertook such studies, we have little that is intelligible or well-founded. The perfection which geometry has acquired since their time puts us in a better position to succeed, and may more than compensate for the advantages that those great minds had over us. ”

“ We have experienced the impenetrability of a material body, we have proven to ourselves that a certain force is required to change its motion, we have seen that the collision of two bodies causes them to stop or be reflected or displace a resting body or, more generally, change their speed. ”

“ It seems that the ancient philosophers made the first attempts at this sort of science, in looking for metaphysical relationships between numbers and material bodies. When they said that God occupies himself with geometry, they surely meant that He unites in that science the works of His power with the perspectives of His wisdom. ”

“ A proof based on the similarity of many animals would seem to be refuted by the infinite variety observed in others. Without comparing their most basic parts, how shall we assess the similarity of an eagle with a fly, a stag with a slug, a whale with an oyster? ”

“ A blind and deterministic mechanics follows the plans of a perfectly clear and free Intellect. If our spirits were sufficiently vast, we would also see the causes of all physical effects, either by studying the properties of material bodies or by studying what would most suitable for them to do. ”

“ To unify the certainty of our research with its breadth, it is necessary to use both types of study. Let us calculate the motion of bodies, but also consult the plans of the Intelligence that makes them move. ”

“ We should at least examine the strengths and weaknesses of each argument, to give each one its proper weight; for one can do no greater damage to Truth than to base it on false reasoning.
I will not consider here arguments based on an infinite Being, arguments that seem to prove that an infinitely perfect Being must exist; for that idea is so sublime that, from our finite vantage point, we cannot find a reliable foundation upon which to build reasoned arguments. ”

“ The laws of motion and equilibrium derived from this principle are exactly those observed in Nature. We may admire the applications of this principle in all phenomena: the movement of animals, the growth of plants, the revolutions of the planets, all are consequences of this principle. The spectacle of the universe seems all the more grand and beautiful and worthy of its Author, when one considers that it is all derived from a small number of laws laid down most wisely. ”

“ But perhaps it is not miraculous that suitable organs are found in species that actually exist, since they help those animals to survive. One might argue that Chance has produced a countless number of individual animals, of which a few were constructed so that they could meet their own needs; the vast number of other individual animals perished since their parts were not suitable for survival. ”

“ If we assume, as seems reasonable, that light moves more quickly in air than it does in water, then the bent path taken by the light causes it to move from its departure point to its arrival point in the briefest possible time. ”

“ If you assume that speed must change by degrees, doesn't it change discontinuously between degrees? Even imperceptible discontinuous changes would violate the law of continuity as much as the sudden destruction of the universe.
The experiments suggest that it is easy to confuse hardness with elasticity, but they do not show that all hard bodies are elastic. On the contrary, those who have considered the impenetrability of bodies suggest that perfect inelasticity is a necessary consequence of matter. ”

“ The first type of studies is more within our power, but does not take us far. The second type may lead us stray, since we do not know enough of the goals of Nature and we can be mistaken about the quantity that is truly the expense of Nature in producing its effects. ”

“ Some of these machines seem highly perfected, whereas others seem like coarse sketches. Many parts seem useless or even harmful based on our present knowledge, unless we assume in advance that they were sent into the world by a all-wise and all-powerful Being. ”

“ To broaden our knowledge of the world, we use different methods that rarely lead us to the same truths. Nevertheless, it would be remarkable if certain fundamental truths of Philosophy could be illustrated by geometric arguments or algebraic proofs. ”

“ This is the principle of least action, a principle so wise and so worthy of the supreme Being, and intrinsic to all natural phenomena; one observes it at work not only in every change, but also in every constancy that Nature exhibits. In the collision of bodies, motion is distributed such that the quantity of action is as small as possible, given that the collision occurs. At equilibrium, the bodies are arranged such that, if they were to undergo a small movement, the quantity of action would be smallest. ”

“ The great Descartes, boldest of the philosophers, sought such laws, but was mistaken. However, time brought the subject of mechanics to a kind of maturity and those laws, unknown for centuries, were developed suddenly in several places at once. ”

“ After meditating deeply on this topic, it occurred to me that light, upon passing from one medium to another, has to make a choice, whether to follow the path of shortest distance (the straight line) or the path of least time. But why should it prefer time over space? Light cannot travel both paths at once, yet how does it decide to take one path over another? Rather than taking either of these paths per se, light takes the path that offers a real advantage: light takes the path that minimizes its action.
The refraction of light Now I have to define what I mean by "action". ”

“ They give the example of a painter who thinks that a circle drawn by hand shows his skill more than one drawn with a compass, never considering that instruments can help in making figures more complex and regular. ”

“ The two alternatives, Intelligent Design versus pure chance, are based on our inability to find a physical cause for the uniformity of planetary motion within Newton's system. However, other philosophers have hypothesized a fluid that transports the planets or at least regulates their motion; if true, that might explain the uniformity of planetary motion (rather than an Intelligent Designer or pure chance) and would be no more proof of God's existence than any other motion imposed on matter.
I don't know whether Newton's argument based on the construction of animals is much better. ”

“ The second law is also the same as that governing the reflection of an elastic ball from an impenetrable surface. Mechanics shows that such a ball is reflected from such a surface so that its angle of reflection equals its angle of incidence, as observed for light.
But the third law still requires a plausible explanation. The passage of light from one medium to another exhibits behavior that is totally different from a ball moving through different media. Every explanation of refraction has some problems that have not yet been overcome. ”

“ These philosophers assign the cause of motion to God because they don't know where else to put it; they resort to an immaterial Being, since they can't imagine that matter should have the power to produce, distribute and destroy motion. But it's important to realize that all the laws of motion and equilibrium should be based on a suitable principle, if we are to use them to prove God's existence, regardless of whether bodies can act directly on each other, or whether they use some other interaction as yet poorly understood. ”