A History of Science: Against the Myths, the Flourishing of Reason

This article is from Les Indispensables de Sciences et Avenir, Issue 212, dated January/March 2023.

The word “flag” has a history that we cannot ignore. Philosopher and historian of science Michel Bly reminds us: “The science of the Greeks is governed by the aspiration to contemplate the ideas of beauty and goodness through sensible appearances; it is therefore inseparable from the ethical conception of the action of knowledge.” Thus, for Aristotle, the bodily quest is part of the contemplative life, which mobilizes the higher part—the reasoning—of the soul, necessary for happiness.

Therefore, ancient science has nothing to do with today’s science, either in its economic and political organization or in its methods. As for the term physis very oldAnd Michelle Bly adds, It has practically nothing to do with the word physics today physis The Greeks are nature, as far as they grow. It includes the principle of tangible and living force, the principle of development that cannot be calculated. “

To mathematically phenomenology it would be necessary to transform the idea of ​​nature. It wouldn’t be until the seventeenth century…but what did the Greeks come to know that made them known as the fathers of a scientific, political or artistic “miracle”? They simply revolutionized the way of thinking. From the VII century BC. JC, Phenomenology takes a resolute rationalist turn with the ‘Physiologists’ of Ionie, in western Asia Minor, particularly the town of Milet.

“There, something unrelated to the previous period happens, which is the legend.”Michael Bly explains. By telling the story of the world or the birth of the gods, by seeking to explain the place of human beings, myth provides the cause of things, and thus includes a certain rationality. But these explanatory elements are fixed, and phenomena are not accounted for by natural principles, but by divine or supernatural entities.

In Miletus, Thales (v. 624-548 BC), first, formulated a theory that explained natural phenomena from the first physical cause: water. He describes air and fire as evaporating water, with solids consisting of condensed water. Given that the earth floats on water, he gave a natural explanation for the earthquakes: no, they are not caused by Poseidon’s wrath, but by the agitation of the waves. His supposed disciple Anaximander (c. 610 – 546 BCE) espouses the idea of ​​the elemental. However, he does not imagine a definite substance, but something infinite, which he calls the infinite or infinite (Aperon), from which the universe originated. while Anaximenes, a supposed disciple of Anaximander, considers the original substance to be air, from which all things come by condensation and rarefaction.

Monetary and rational exchanges

Before the Ionians, the Babylonians, Egyptians, and Chinese had observed nature, sometimes recording the positions of planets for centuries. But the use of these astronomical records remained above all religious, and was confined to the circle of priests. Michel Blay asserts that this is no longer the case with the Ionians: “We must not confuse the religious use and systematization of knowledge in order to construct a science. By their deductive order, which propagates demonstrations starting from clearly defined principles, the Ionians make these demonstrations accessible to all. Everyone can use them. Appropriate and critique them.” Each philosopher discusses his master’s treatises, so that reflection on nature is part of the critical and rational exchanges.

But why did rationalism emerge in this part of the world? David Lefebvre, professor of the history of ancient philosophy at the Sorbonne, points out this during the so-called ancient period (750-490 BC)The city of Miletus and its region was the most developed, the most prosperous, and the most powerful in the Greek world. This shift in thinking can also be explained by the importance of public speaking. “The rhetoric that develops, with the debates at political assemblies, assumes a very good reflection of causation”he points to.

But some thinkers soon find problematic the knowledge of the external world conveyed by the senses. Parmenides of Elea (late 6th century – mid 5th century BC) even argues for the truth of change, asserting that being is immutable and eternal. He was followed by Zeno of Elea (v.490 – v. 430 BC), who formulates his famous Paradoxes on the Movement. In the Aporea of ​​Achilles and the Tortoise, the faster Greek hero never catches up with the animal he left long before him. This person continues to advance while the Achilles catches up to their previous position, so much so that movement seems impossible! Denying the existence of changeAnd The Eleans thought they were destroying the natural science projectDavid Lefebvre says, On the contrary, they played an important role in its development.

When Democritus imagined the atom, the indivisible element, the void…

Physicists must respond to this rejection of motion. Empedocles (c. 490 – 430 BC) asserts that the four elements (earth, air, water, fire) have always existed and produce change by their mixing and separation under the influence of two opposing forces, love and conflict. Another ingenious physical theory, formulated by Anaxagoras (v. 500 – v. 428 BC): The universe was formed without birth or destruction, because nothing comes from nothing, from a motive cause, the mind, which made the universe move and created composite beings. This is true of this epoch qu’apparait l’atomisme, with Leucippe and his eldest Democrite (v. 460 – 370 av. J. -C.), which postulates that the realities of the elements are insecables – the atoms – and Void. Objects are formed from the location and arrangement of the colliding atoms in the space in which they are moving.

The universe according to Democritus. This 17th-century artist’s view shows three concentric regions of the universe imagined by the atomic world of the 5th century BC: Earth and the planets, overlooked by the sky and stars, all surrounded by an “infinite chaos of atoms.” Credit: SPL/SUCRÉ SALÉ

The Greek scientist of the fifth century BC produced a great diversity of causal explanations for natural phenomena, and developed sharp conceptual exchange. Athens, at its peak, became a center of intellectual activity. In the school founded by Socrates, at the Academy, Aristotle (384 – 322 BC) trained and taught for twenty years. Teacher of Alexander the Great and founder of the Lycée in turn circa 335 BC. BC, Aristotle was described by Dante as “Master who knows She bequeathed to Western thought a physics of unparalleled explanatory scope and power.

While Plato asserted that there is only one supreme science, dialectics, which allowed through dialogue to know all that is, Aristotle, on the contrary, introduced a managerial conception of knowledge, in which each science studies only one type of existence.says David Lefebvre. Physics no longer deals with all that exists as with the ionic physicists, but only with physical and moving realities. . ” However, its scope is broad as it relates to atmospheric, astronomical, animal, plant and psychological phenomena.

Against Plato and his idea of ​​\u200b\u200bthe indistinctness of the formation of the sensible world, his gaze focused on the paradigm of sensible forms – the only truth, to which only the mind has access – Aristotle defends the intelligibility and reality of our world. If this terrestrial realm does not provide the perfect movement of the planets in the sky, it nonetheless presents some regularity under its changeable and deceptive appearances. Subject (ousia), defined as a composite of matter and form – what a thing is -, forms the basis of all variable characters or incidents (quantity, quality, relation, position…). Through change, matter receives an occasional modification, but remains the same. Thus, the deciduous tree loses its leaves in the cold season, without ceasing to be the same tree. Aristotle also describes change by means of the basic concepts of agency and action, agency denoting what is in practice, and disposition by what is fully accomplished or achieved. It is possible that every human being has a language, but it is through learning a language that he achieves this ability.

Stagirite bases this search for principles on a theory of four causes: it is possible to explain a phenomenon or an object by its physical cause (its matter), its formal cause (what it is), its kinetic cause (what drives change) and its ultimate cause (that for which it exists). . Aristotle denies that nature is moved by the design of a higher intelligence, but he considers natural processes ordered to an essential end, which they carry within themselves, like a seed that becomes a tree.

His theory of the constituents of matter seems less innovative. “Aristotle accounts for the four elements (water, earth, fire, air) from two pairs of opposites (hot/cold, dry/wet)”David Lefebvre explains. Thus, the evaporation of water is explained by the transformation of cold wet into hot wet.

“The philosopher gave a very effective description of the world.”, as Michelle Bly believes. It was so effective that in the West, thanks to the rediscovery of the great Greek texts inherited by Islamic culture for the first time, It would be reincorporated into the knowledge of the clergy in the thirteenth century by Thomas Aquinas. From this date Aristotle revised theology became a constant part of thought, and that until the seventeenth century! Reversing this tradition must muster geniuses of the caliber of Galileo and Descartes.

Physics in 30 Years, Michel Blay, Philosopher and Historian of Science, Director Emeritus of Research at CNRS

“Il est impossible d’imaginer ce que sera la physique dans treente ans, mais je crains qu’il ne se passe rien. remettra en cause. France, the current budgets that allow realizing travaux a trinity or quarante ans diminuent, tandis que les projets de l’Agence nationale de la recherche qui glanent le maximum d’argent, tels les les projets europeens, sont des projets a trois or quatre years.

Max Planck worked twenty or thirty years to establish quantum mechanics! By building a new collider with a thousand times the budget that discovered the Higgs boson, we will find a new particle, but this will not bring anything. We must challenge the Standard Model of Physics, which none of the current experiments can do. We are in a monotonous period, which is squeezing the old frameworks, those of general relativity and quantum mechanics, to the limit, because the issues are no longer those of theoretical knowledge, but of technological applications. There will be no genius in this environment. Geniuses appear only in an environment that supports the possibility of action.

Written by François Follet