Philosophy of the Modern Era

The Development of Science

Almost everything that distinguishes the present age from earlier centuries can be attributed to science, which achieved its most remarkable advancements in the seventeenth century. The Italian Renaissance, while not belonging to the Middle Ages, also does not fit neatly into the Modern era; it can be likened to the finest period of Greece. The sixteenth century, marked by an overwhelming presence of theology, is more medieval than the world of Machiavelli. The Modern age, insofar as it concerns spiritual values, begins with the seventeenth century. There is no Italian from the Renaissance period whom Plato or Aristotle would not understand; Luther would horrify Thomas Aquinas, yet Aquinas would find it relatively easy to comprehend him. The situation changes with the seventeenth century: Plato and Aristotle, Thomas Aquinas and Ockham would find Newton incomprehensible.

The new concepts advanced by science profoundly influenced the emerging philosophy. Descartes, who is considered the founder of modern philosophy in a certain sense, was himself one of the creators of the science of the seventeenth century. To grasp the spiritual atmosphere of the time that gave rise to this new philosophy, it is essential to briefly discuss the methods and achievements in astronomy and physics.

In the development of science, four great figures hold a prominent place: Copernicus, Kepler, Galileo, and Newton. Among them, Copernicus lived in the sixteenth century but had little influence during his lifetime.

Copernicus (1473—1543) was a Polish cleric of impeccable faith. In his youth, he traveled to Italy and absorbed the Renaissance spirit. By 1500, he was a professor of mathematics in Rome, but he returned to his homeland in 1503, where he became a canon in Frombork. While it appears he devoted much of his time to battling the Germans and reforming the monetary system, he dedicated his leisure hours to astronomy. He soon became convinced that the Sun is the center of the universe and that the Earth has a dual motion: daily rotation and yearly orbit around the Sun. Fear of church censorship compelled him to delay the publication of his views, though he did not prevent them from becoming known. His principal work, "On the Revolutions of the Heavenly Spheres," was published in the year of his death (1543) with a preface by his friend Osiander, which stated that the heliocentric theory was merely proposed as a hypothesis. It remains unclear to what extent Copernicus sanctioned this assertion, but this issue is not particularly significant, as he made a similar statement in his book. The book was dedicated to the pope and escaped official condemnation by Catholicism until the time of Galileo. In the years when Copernicus lived, the Church was more liberal than it became after the Council of Trent, the Jesuits, and the revived Inquisition did their work.

In spirit, Copernicus's work is not modern; it could be characterized as Pythagorean. He assumes as axiomatic that all celestial movements must be circular and uniform, and, like the Greeks, he falls under the influence of aesthetic motives. In his system, there are still epicycles, although their centers are positioned on or rather near the Sun. The fact that the Sun is not precisely at the center complicates the simplicity of his theory. Although he was somewhat familiar with Pythagorean doctrines, he seems unaware of the heliocentric theory of Aristarchus of Samos, yet there is nothing in his constructions that a Greek astronomer could not have arrived at. Indeed, what was significant in his work was the debunking of the notion of the Earth as a unique geometric center. Ultimately, based on Copernicus's theory, it became difficult to acknowledge the cosmic significance attributed to humanity by Christian theology, but such conclusions from his theory would not have been accepted by Copernicus, whose orthodox faith was sincere and who protested against the view that his theory contradicted the Bible.

Copernicus's theory had genuine difficulties, the greatest of which was the absence of stellar parallax. If the Earth, at any point in its orbit, is 283,664,000 km away from the point it will occupy in six months, this should induce changes in the apparent positions of the stars, just as a ship positioned directly north of one point on the shore cannot remain directly north of another point. However, no parallax was observed, and Copernicus rightly concluded that the fixed stars must be significantly farther away from us than the Sun. Only in the nineteenth century, when measurement techniques became sufficiently accurate, was it possible to observe stellar parallax, and even then, only for a few nearby stars.

Another difficulty arose concerning falling bodies. If the Earth is constantly rotating from west to east, then a body thrown from a certain height cannot fall to a point directly vertical to the place from which it began to fall but will land somewhat to the west, as the Earth will have moved a distance during the time of the body's fall. This difficulty was addressed using Galileo's law of inertia, but no answer could be found in Copernicus's time.

An interesting book by E. A. Bart titled "The Metaphysical Foundations of Modern Physical Science" (1925) compellingly discusses many unfounded assumptions made by the individuals who created modern science. He rightly points out that in Copernicus's time, there were no facts that would necessitate acceptance of his system, but there was a range of facts that argued against it. "Modern empiricists, had they lived in the sixteenth century, would have been the first to ridicule the new philosophy of the universe." The primary aim of the book is to discredit modern science by suggesting that its discoveries were fortunate accidents arising from superstitions as deep as those of the Middle Ages. I believe this reveals a misunderstanding of the scientific approach by the book's author: what distinguishes a scientist is not what he believes but how and why he believes it. His beliefs are not dogmatic but experiential. They are based on evidence, not authority or intuition. Copernicus was justified in labeling his theory a hypothesis; his opponents mistakenly assumed that new hypotheses were undesirable.

Those who founded modern science possessed two virtues that do not always accompany one another: immense patience in observation and great courage in proposing hypotheses. The latter was characteristic of early Greek philosophers, while the former was largely present among the later astronomers of antiquity. Yet none of the ancients, save perhaps Aristarchus, possessed both virtues simultaneously, nor did anyone possess them during the Middle Ages. Copernicus, like his great successors, possessed both. He knew everything that could be known about the visible motions of celestial bodies across the celestial sphere using the instruments available in his day and understood that the hypothesis of the Earth’s daily rotation was more economical than the hypothesis of the circular motion of all celestial spheres. According to contemporary views, which regard all motion as relative, simplicity is the sole benefit of Copernicus’s hypothesis, but neither he nor his contemporaries thought so. As for the Earth’s annual rotation, there was also simplification here, though not as pronounced as with the daily rotation. Indeed, Copernicus still needed epicycles, albeit to a lesser extent than required in Ptolemy’s system. Only after the discovery of Kepler's laws did the new theory achieve its ultimate simplicity.

In addition to the revolutionary impact on understanding the cosmos, the new astronomy had two further significant merits: the first was the recognition that everything believed since ancient times might be false; the second was that the verification of scientific truth consists of patiently gathering facts alongside boldly conjecturing the laws that unify these facts. Neither of these merits was as fully developed in Copernicus as in his successors, but both were already manifest in his work.

Some of those whom Copernicus acquainted with his theory were German Lutherans, but when Luther learned of it, he was deeply shocked. "People," he said, "listen to a presumptuous astrologer who strives to demonstrate that the Earth revolves, not the heavens or the celestial vault, the Sun and the Moon. Anyone who wishes to appear smarter must invent some new system, which, of course, is the best of all systems. This fool seeks to overturn all astronomy, but Sacred Scripture tells us that Joshua commanded the Sun to stand still, not the Earth." Similarly, Calvin refuted Copernicus with a biblical text: "The world is firmly established, it cannot be moved" (Psalms 92(93), 1), exclaiming, "Who dares to place the authority of Copernicus above the authority of the Holy Spirit?" The Protestant clergy were at least as fanatical as their Catholic counterparts; nonetheless, in Protestant countries, a significantly greater free thought soon emerged than in Catholic ones, as the clergy held less power there. An important aspect of Protestantism was not heresy but schism, as the latter led to the formation of national churches, which lacked sufficient power to control secular authority. Overall, this can be viewed as a gain, for churches everywhere opposed, to the best of their abilities, any innovation that contributed to the increase of happiness or knowledge here on Earth.

Nicolaus Copernicus lacked the means to provide any exhaustive proof for his hypothesis, and for a long time, astronomers rejected it. The next significant astronomer was Tycho Brahe (1546—1601), who occupied an intermediate position: he believed that the Sun and Moon revolved around the Earth, while the planets revolved around the Sun. In terms of theory, he was not particularly original. However, he presented two compelling arguments against Aristotle’s view that everything in the celestial realm is unchanging. One argument was the appearance of a new star in 1572, which, as established, exhibited no daily parallax and thus must be farther away than the Moon. The second argument arose from observations of comets, which were also found to be more distant than the Moon. The reader will recall Aristotle's theory that change and destruction pertain only to the sublunary world; this theory, like other Aristotelian theories concerning scientific matters, impeded scientific progress.

Tycho Brahe is significant not as a theorist but as an observer: initially supported by the King of Denmark and later by Emperor Rudolf II, he compiled a stellar catalog and meticulously recorded the positions of planets over many years. By the end of his life, his assistant was Johannes Kepler, then a young man. For Kepler, these observations were invaluable.

Kepler (1571—1630) exemplifies one of the most remarkable instances of what can be achieved without being a genius through sheer patience. He was the first major astronomer after Copernicus to adopt the heliocentric theory; however, Tycho Brahe's observations indicated that it could not be entirely correct in the form presented by Copernicus. Influenced by Pythagoreanism, Kepler was more or less unwittingly inclined toward sun worship, even though he was a devout Protestant. These motivations undoubtedly compelled him to adhere to the heliocentric hypothesis. Yet, his Pythagoreanism led him to assign, as Plato did in the "Timaeus," cosmic significance to the five regular polyhedra. He employed them to propose hypotheses aligning with his views, and ultimately, through a stroke of fortunate chance, one of these proved successful.

Kepler's greatest achievement was the discovery of the three laws of planetary motion. He published two of them in 1609 and the third in 1619. His first law states: planets move in ellipses, with the Sun at one of the foci. The second law states: the line connecting a planet to the Sun sweeps out equal areas in equal intervals of time. The third law asserts: the squares of the orbital periods of the planets are proportional to the cubes of their average distances from the Sun.

A few words should be said to elucidate the importance of these laws. The first two laws, during Kepler's time, could be demonstrated only with respect to Mars; concerning other planets, observations indicated that their movements conformed to the first two laws, but not sufficiently for one to claim an exact correspondence between observed data and the laws. However, a decisive confirmation soon emerged.

The discovery of the first law, which states that planets move in ellipses, demanded substantial effort to liberate oneself from traditions that the modern mind can now clearly comprehend. The only consensus among all astronomers was that all celestial movements are circular or composed of circles. Where it was found that circles were insufficient to explain the motions of the planets, epicycles were employed. An epicycle is a curve described by a point on a circle rolling around another circle. For example, take a wheel and secure it flat on the ground; then take another, smaller wheel, into whose rim a nail is driven, and roll the smaller wheel (also flat on the ground) around the larger wheel so that the tip of the nail touches the ground. The path traced by the nail on the ground will be the epicycle. The orbit of the Moon concerning the Sun is of a similar nature: the Earth describes an almost circular path around the Sun, while the Moon simultaneously describes a circle, revolving in its orbit around the Earth. However, this is only approximately true. As observations became more precise, it was established that no system of epicycles accurately reflected reality. Kepler's hypothesis, as he formulated it, aligned far better with Mars's motion than either Ptolemy's or even Copernicus's hypotheses.

The substitution of circles for ellipses entailed a rejection of the aesthetic inclination that had guided astronomy since Pythagoras. The circle was the perfect figure, and the celestial bodies were perfect bodies (originally divine), closely associated even in Plato's and Aristotle's works with the divine. It seemed evident that a perfect body must move in a perfect figure. Moreover, since celestial bodies move freely, without external influence, their motion must be "natural." It was now easy to assume that it was in the circle, not in the ellipse, that something "natural" resided. Thus, many deeply rooted prejudices had to be cast aside before Kepler's first law could be accepted. No ancient thinker—not even Aristarchus of Samos—foresaw such a hypothesis.

The second law is associated with the variation in a planet's speed at different points in its orbit. If S is the Sun, and P1, P2, P3, P4, P5 are the successive positions of the planet at equal intervals of time, say, one month, Kepler's law asserts that the areas P1SP2, P2SP3, P3SP4, and P4SP5 are equal to one another. Thus, the planet moves fastest when it is closest to the Sun and slowest when it is farthest from it. This again contradicted all existing notions: a planet was deemed too majestic to alternate between accelerating and decelerating its motion.

The third law is important because it compares the movements of different planets, whereas the first two laws pertain only to individual planets. The third law states: if r is the average distance of a planet from the Sun and T is the duration of its year, then the ratio of r³ to T² is the same for all planets. This law provides evidence (as far as the Solar System is concerned) for Newton's law of inverse proportionality of gravitational force to the square of the distance. But this will be addressed further below.

Galileo (1564—1642) is, except perhaps for Newton, the greatest of the founders of modern science. He was born almost on the same day that Michelangelo died and passed away in the same year that Newton was born. I mention these facts for those (if indeed any exist) who still believe in metempsychosis. He is of great significance as an astronomer but perhaps even more so as the founder of dynamics.

Galileo was the first to uncover the significance of acceleration in dynamics. "Acceleration" signifies a change in speed, either in magnitude or direction; thus, a body moving uniformly in a circle experiences acceleration at every moment directed toward the center of the circle. In terms customary before Galileo's time, one could say that he regarded uniform motion in a straight line as the only "natural" state both on Earth and in the heavens. Previously, it was thought that for celestial bodies, it was "natural" to move in circles, while for earthly bodies, it was natural to move in straight lines; however, it was believed that moving terrestrial bodies would gradually cease their motion if left to themselves. Contrary to this view, Galileo asserted that any body, if left to itself, would continue to move in a straight line at a constant speed; any changes in speed or direction of motion are explained by the action of some "force." This principle was proclaimed by Newton as the "first law of motion." It is also referred to as the law of inertia. I shall return to its content below; for now, it is necessary to pause on some details of Galileo's discoveries.

Galileo was the first to establish the law of falling bodies. This law, which introduces the concept of "acceleration," is extremely simple. It states that when a body falls freely, its acceleration remains constant, disregarding the resistance that air may provide; moreover, the acceleration is the same for all bodies, whether heavy or light, large or small. However, it was impossible to prove this law exhaustively until the invention of the air pump around 1654. After this invention, it became possible to observe the fall of bodies in conditions that could practically be deemed close to a vacuum, and it was established that feathers fall at the same rate as lead. Thus, Galileo demonstrated that there is no noticeable difference between a large piece and a small piece of the same substance. Prior to him, it was assumed that a large piece of lead would fall faster than a small one, but Galileo experimentally proved that this was not the case. Measurements in his time were not as precise as they later became; yet, despite this, he arrived at the correct formulation of the law of falling bodies. If a body falls freely in a vacuum, its speed increases by a constant amount. At the end of the first second, its speed equals 9.8 m/s; at the end of the second, it is 19.6 m/s; at the end of the third, it is 29.4 m/s, and so forth. The acceleration, that is, the amount by which speed increases, remains constant: every second, speed increases by approximately 9.8 m/s.

Galileo also studied the flight of projectiles—a subject of considerable importance to his employer, the Duke of Tuscany. At that time, it was believed that a projectile launched horizontally would move horizontally for a while and then suddenly begin to fall vertically. Galileo demonstrated that, ignoring air resistance, the horizontal velocity would remain constant according to the law of inertia, while the vertical velocity would increase in accordance with the law of falling bodies. To ascertain how a projectile would move during a brief interval, say one second, after it had been in flight for some time, we proceed as follows. First, if it did not fall, it would cover a certain horizontal distance equal to what it covered in the first second of its flight. Second, had it not moved horizontally but simply fallen, it would descend vertically with a speed increasing proportionally to the time elapsed since the initial moment of its flight. In fact, the change in its position would be as if, for the first second, it moved horizontally at the initial speed, and then for the next second, it fell vertically with a speed increasing in proportion to the time of its flight. Simple calculations reveal that the resulting trajectory is a parabola, a conclusion supported by observations provided air resistance is disregarded.

The above presents a straightforward example of a principle that proved immensely useful in dynamics—the principle stating that when several forces act simultaneously, the result is as if each force acted in succession. This is part of a more general principle known as the law of the parallelogram. Suppose, for instance, you are on the deck of a moving ship and walking across it. During your walk, the ship travels a certain distance, so relative to the water, you have advanced both along and across the direction of the ship’s movement. If you wish to determine your position relative to the water, you can assume that initially, you stood still while the ship moved, and then, for the same time interval, the ship stood still while you walked across it. The same principle applies to forces. This allows us to ascertain the overall result of a series of forces and to analyze physical phenomena by revealing the specific laws governing the various forces acting on moving bodies. It was Galileo who introduced this remarkably fruitful method.

Above, I endeavored to speak as much as possible in the language of the seventeenth century. Modern language differs significantly; however, to explain the achievements of the seventeenth century, it is beneficial to adopt the expressive style characteristic of that time.

The law of inertia elucidated a mystery that the Copernican system had been unable to solve prior to Galileo. As mentioned, if you drop a stone from the top of a tower, it will fall to the base rather than land somewhere to the west of it; yet if the Earth is in rotation, it must traverse a certain distance during the stone's descent. The reason the stone does not deviate is that it retains the rotational velocity that it shares with all other bodies on the Earth’s surface. In fact, if the tower were sufficiently high, the result would be contrary to what the opponents of Copernicus expected. The top of the tower, being farther from the center of the Earth than its base, moves faster; hence the stone should fall slightly to the east of the tower's base. However, this effect is too minuscule to be measurable.

Galileo passionately defended the heliocentric system; he corresponded with Kepler and concurred with his findings. Upon hearing that a certain Dutchman had invented the telescope, Galileo constructed one himself and soon discovered a series of significant phenomena. He found that the Milky Way is composed of numerous individual stars. He observed the phases of Venus, whose existence, as Copernicus had known, logically followed from his theory but which the naked eye could not perceive. He discovered the moons of Jupiter, which he named the "Medicean stars" in honor of his patron. It was established that these moons adhered to Kepler’s laws. However, a difficulty arose. There had always been seven celestial bodies: five planets, the Sun, and the Moon; thus, seven was a sacred number. Is not Sunday the seventh day? Are not candlesticks seven-branched, and are there not seven churches in Asia? What could be more fitting than to assert that there must also be seven celestial bodies? But if one must add four moons of Jupiter, it would total eleven— a number devoid of any mystical properties. On this basis, traditionalists denounced the telescope, refused to look through it, and claimed that all discoveries made with the telescope were mere illusions. Galileo wrote to Kepler expressing his desire to mock the folly of the "crowd"; at the end of his letter, it became clear that the "crowd" referred to the professors of philosophy who attempted to dismiss Jupiter’s moons using "sophisms as if they were magical incantations."

As is well known, Galileo was condemned by the Inquisition first secretly in 1616 and then publicly in 1633; in the latter case, he recanted his theories and promised never again to assert that the Earth rotates on its axis or revolves around the Sun. The Inquisition succeeded in halting the development of science in Italy, which did not revive there for centuries. However, it could not prevent scholars from accepting the heliocentric theory, and its obstinacy inflicted significant damage on the church. Fortunately, there were Protestant countries where priests, also eager to harm science, could not achieve control over the state.

Newton (1642—1727) achieved the ultimate and complete triumph prepared by Copernicus, Kepler, and Galileo. Based on his three laws of motion (the first two of which he owed to Galileo), he proved that Kepler’s three laws are equivalent to the assertion that each planet at any given moment has an acceleration directed towards the Sun and changing inversely proportional to the square of its distance from it. He showed that the acceleration towards the Earth and the Sun explained the Moon's motion according to the same formula, and that, under the law of inverse proportionality to the square of distance, the acceleration of bodies falling to the Earth’s surface is akin to the acceleration of the Moon. He defined "force" as the cause of a change in motion speed, that is, acceleration. Thus, he was able to articulate his law of universal gravitation: "Every body attracts every other body with a force directly proportional to the product of their masses and inversely proportional to the square of the distance between them." From this formulation, he could derive everything else in planetary theory: the motion of planets and their moons, the orbits of comets, the tides. It later became evident that even the smallest deviations from elliptical orbits exhibited by planets were explained by Newton's laws. The triumph was so complete that Newton risked becoming the second Aristotle and an insurmountable barrier to progress. In England, it took a century after his death for people to sufficiently free themselves from his authority to create genuinely original works on the issues he had explored.

The seventeenth century was remarkable not only for astronomy and dynamics but also in many other fields related to science.

Let us first address the issue of scientific instruments. The complex microscope was invented shortly before the beginning of the seventeenth century, around 1590. In 1608, the telescope was invented by the Dutchman Lippershey, although it was Galileo who first employed it seriously for scientific purposes. Galileo also invented the thermometer, or at least this seems the most likely attribution. His pupil, Torricelli, invented the barometer. Guericke (1602—1686) invented the air pump. Clocks, although not newly created, were significantly improved in the seventeenth century, primarily due to the work of Galileo himself. Thanks to these inventions, scientific observations became considerably more precise and more extensive than ever before.

Moreover, there were significant contributions in other sciences aside from astronomy and dynamics. Gilbert (1540—1603) published his major work on magnetism in 1600. Harvey (1578—1657) discovered the circulation of blood and published his findings in 1628. Leeuwenhoek (1632—1723) discovered spermatozoa, although it seems that Stephan Hales discovered them a few months earlier; Leeuwenhoek also discovered protozoa or single-celled organisms, and even bacteria. Robert Boyle (1627—1691) was, as children were taught in my youth, "the father of chemistry and the son of the Earl of Cork"; he is now primarily known for "Boyle's law," which states that for a given amount of gas at a given temperature, the pressure is inversely proportional to the volume.

I have yet to speak of the triumphs of pure mathematics, which have indeed been profound and essential for successful endeavors in the physical sciences. In 1614, Napier published his invention of logarithms. Analytical geometry emerged from the work of several mathematicians in the seventeenth century, with the greatest contribution made by Descartes. Differential and integral calculus was independently discovered by Newton and Leibniz, becoming a tool for almost all advanced mathematics. These represent merely the most outstanding achievements in pure mathematics, though there existed a multitude of other significant discoveries.

The consequence of this scientific activity we have examined was a complete transformation in the views of educated individuals. At the beginning of the century, Thomas Browne participated in witch trials; by the end of the century, such a thing would have been utterly inconceivable. In Shakespeare's time, comets were still regarded as miraculous; after the publication of Newton's "Principia" in 1687, it became known that he and Halley had calculated the orbits of certain comets, demonstrating that comets, like planets, were subject to the law of gravitation. The power of law established its dominion over thought, rendering such things as magic and witchcraft incredible. By 1700, the worldview of educated people was thoroughly modern, whereas in 1600, save for a few, it was largely medieval.

In the remainder of this chapter, I shall endeavor to briefly illuminate the philosophical views that appear to be a consequence of the science of the seventeenth century, along with some aspects that distinguish modern science from that of Newton.

The first point to note is the near elimination of all traces of animism from the laws of physics. The Greeks, though not articulating it clearly, evidently regarded the force of motion as a sign of life. A rational observer would perceive that animals move of their own accord, while inanimate matter moves only when compelled by an external force. According to Aristotle, the soul of an animal possesses various functions, one of which is to animate the body. The sun and planets, in the view of the Greeks, were worthy of divine status or, at the very least, were governed and moved by divine beings. Anaxagoras thought otherwise, but he was deemed an impious thinker. Democritus had similar thoughts, yet they were overlooked in favor of Plato and Aristotle by all except the Epicureans. Aristotle's forty-seven or fifty-five unmoved movers were divine spirits, the primary source of all celestial motion. Left to its own devices, any inanimate body would soon become motionless; thus, the influence of the soul on matter must be continuous to prevent the cessation of movement.

The discovery of the first law of motion altered this understanding. Inanimate matter, once set in motion, continues to move until some external cause halts it. Moreover, the external causes of change in motion turned out to be material whenever they could be definitively established. In any case, the solar system preserved its motion through its own momentum and its own laws; no external intervention was required. It may have seemed that God was still necessary to set the entire mechanism in motion; according to Newton, the planets were initially set in motion by God's hand. Yet, once God initiated the movement of the planets and established the law of gravitation, everything proceeded autonomously, without further divine intervention. When Laplace suggested that the very forces acting now may have been the cause of the formation of the planets, which emerged from the sun under the influence of these forces, God's role in the development of nature diminished further. He could remain the creator, but even that was uncertain, as it was unclear whether the world had a beginning in time. Although most scholars exhibited piety, the perspective arising from their scientific endeavors posed a threat to religion, and it was entirely natural for theologians to be alarmed.

Another significant consequence of the advancement of science was a profound shift in the conception of humanity's place in the cosmos. In the Middle Ages, Earth was viewed as the center of the heavens, with everything serving humanity's purpose. In the Newtonian world, Earth was a minor planet, an unremarkable star; astronomical distances were so vast that, in comparison, Earth was but a pinhead. It seemed incredible that this vast mechanism was designed for the benefit of some pitiful creatures inhabiting that pinhead. Furthermore, the purpose that had constituted the inner dimension of scientific concepts since Aristotle was now excluded from the scientific process. Perhaps some still believed that the heavens existed to proclaim the glory of the Lord, but no one could permit that belief to interfere with astronomical calculations. The world might have a purpose, but it could no longer be considered in scientific explanations of nature.

The Copernican theory ought to have humbled human pride; yet, in reality, the opposite occurred, for the triumph of science revived human pride. The dying ancient world was tormented by a sense of sin and bequeathed it as a heavy burden to the Middle Ages. To be humble before God was both right and prudent, as God would punish pride. Epidemics, floods, earthquakes, the Turks, the Tatars, and comets bewildered those gloomy centuries, and it was believed that only increasing humility could avert these real or impending disasters. However, it became impossible to remain humble when humanity had achieved such progress.

Nature and her laws lay hidden in darkness,
But God said, “Let there be Newton,” and it was light.

As for eternal torments, it is likely that the creator of such a vast universe had more pressing matters than sending people to hell for minor deviations from religion. Judas Iscariot could be condemned to eternal torment, but not Newton, even though he was an Arian. Certainly, there were many other important reasons for people to feel content with themselves. The Tatars were contained within Asia and ceased to pose a threat; the Turks had also lost their menace, and Halley, with his discovery, rendered comets harmless. As for earthquakes, while still formidable, they had become so interesting that scholars could hardly regret their occurrence. Western Europeans quickly amassed wealth and became masters of the world: they conquered North and South America, dominated Africa and India, commanded respect in China, and inspired fear in Japan. With the addition of the triumph of science to all this, it is no wonder that the people of the seventeenth century felt like living beings rather than miserable sinners, as they still referred to themselves in Sunday services.

In some respects, the concepts of modern theoretical physics differ from the views of the Newtonian system. First and foremost, it has been established that the notion of "force," which was one of the leading concepts in the seventeenth century, is unnecessary. For Newton, "force" is the cause of a change in motion in magnitude or direction. The concept of cause is regarded as significant, while force, understood metaphorically, is akin to what we experience when we push or pull. In such an understanding of force, there arose an objection to the acknowledgment of gravitation, as it acted at a distance, and Newton himself conceded that some medium must exist through which it is transmitted. Gradually, it was established that all equations could be formulated without introducing forces. What is observable is the relationship between acceleration and position; to assert that this relationship is created by "force" adds nothing to our understanding. Observation shows that at every moment, the planets possess acceleration directed toward the sun, which varies inversely with the square of their distances from it. To say that it is due to the "force" of gravitation is merely a tautology, akin to claiming that opium induces sleep because it possesses sedative properties. Therefore, the modern physicist merely establishes a formula that defines acceleration while simultaneously avoiding the term "force." The concept of "force" is an unclear specter of vitalistic notions concerning the causes of motion, and gradually, this specter has been expelled.

Until the advent of quantum mechanics, there had been no discoveries in science that altered, in any significant way, the fundamental meanings of the first two laws of motion, namely that the laws of dynamics must be formulated in terms of acceleration. In this regard, both Copernicus and Kepler can still be grouped with the ancients; they sought laws that would determine the shapes of the orbits of celestial bodies. Newton made it clear that the laws formulated in this manner could only be approximately true. The planets do not move in perfect ellipses due to perturbations caused by the influences of other planets, and the orbits of the planets never exactly repeat for the same reason. However, the law of gravitation, which is related to accelerations, was very simple and was considered entirely accurate for two centuries after Newton. Even when corrected by Einstein, it remained a law linked to accelerations.

Indeed, the law of conservation of energy is a law associated with velocities rather than acceleration. However, in the calculations that employ this law, acceleration is still taken into account.

The changes introduced by quantum mechanics are profound, yet the question remains somewhat contentious and undefined.

One alteration to Newtonian philosophy that merits mention now is the rejection of absolute space and time. The reader may recall this issue being discussed in connection with Democritus. Newton believed in space composed of points and time formed from moments that exist independently of the bodies and events contained within them. To support his view on space, he presented an empirical argument: physical phenomena allow us to distinguish absolute rotation. If water in a bucket is spun, it rises at the sides and falls in the center; however, if the bucket itself is rotated instead of the water, this outcome does not occur. Since then, experiments have been conducted, such as the Foucault pendulum, which provides what is considered evidence of the Earth's rotation. Even from the standpoint of the most contemporary views, the issue of absolute rotation presents challenges. If all motion is relative, the distinction between the hypothesis that the Earth rotates and the hypothesis that the heavens rotate is purely verbal—it is no greater than the difference between the statements "John is the father of James" and "James is the son of John." However, if the heavens are rotating, then the stars must move at speeds exceeding that of light, which is deemed impossible. It cannot be said that the modern resolution of these difficulties is entirely satisfactory, but it is sufficiently so that almost all physicists accept the viewpoint that motion and space are purely relative. This, along with the unification of space and time into spacetime, has significantly altered our perspective on the Universe compared to that which emerged from the works of Galileo and Newton. Yet, I shall not dwell further on this, nor on quantum mechanics.