Natural philosophy, known in Latin as philosophia naturalis, is an expression that applied to the objective study of nature and the physical universe that reigned before the development of modern science. Traditionally allied with natural theology, it used to designate all the astronomical, physical, chemical and biological sciences. Natural philosophy was distinguished from moral philosophy, which meant not only morality and ethics, but also the theory of knowledge, psychology, sociology, politics, and aesthetics.
Origins of the expression
The word natural derives from Latin, in which it has the same meaning.
The word physical has as etymology the Greek word phusikê, which means knowledge of nature.
During the twelfth century, physics covered two areas: medicine, and natural sciences (eg a doctor is a physician).
From the end of the fifteenth century, the physical word designated science of natural causes. The chairs of natural philosophy established in the ancient universities created in the thirteenth century, included all the natural sciences, according to an academic corpus that was based on the philosophy of Aristotle.
The word “physics” took on its modern meaning, which is narrower than the original meaning, from the seventeenth century (Galileo, Descartes), and especially the classical physics that was born with Newton. The word “physical” is used in its current meaning since 1690.
What marked a turning point in mentalities was the famous trial of Galileo (1633), and the philosophical reaction of Descartes. He wrote in his Discours de la méthode (1637) that man was to become “master and possessor of nature”. At the turn of the seventeenth century and the eighteenth century, Isaac Newton’s scientific treatise (1687) began to form the mathematical principles of “natural philosophy.” The revolution that constituted the awareness that the earth revolved around the sun (heliocentrism), had led to changes of mentality: it was realized that it was possible to explain this phenomenon by expressing equations in mathematical language, thanks to theories of differential and integral calculus.
“Natural philosophy” was the usual term preceding our current term of “science”, when the theme of the study was “the work of nature”. “Modern science” (scientia in Latin which means “knowledge”) was able to acquire the status carried by “natural philosophy” when pure deduction, combined with inductive methods of acquiring knowledge, reached an established result on natural phenomena, without the support of Revelation. Recall that in general logics, which rests on the philosophical foundations of Aristotle, induction is one of the three types of inference, with deduction and abduction. The experimental method, empirical in nature, relies largely on induction.
Forms of “science” have developed historically from philosophy, or from what was considered to be “natural philosophy” in the historical context of the constitution of “Philosophy”. The notions we usually have of science and scientists date back only to the nineteenth century.
The term was resurrected during the the 19th century in the context of the creation and evolution controversy by those who were concerned that science does not accept supernatural explanations.
Contrary to popular belief, natural philosophy has not been replaced by natural science or natural theology, and continues to cultivate its specificity in many areas that are distanced from scientism as well as doctrines of the supernatural. One of the places where this reflection flourishes is the Circle of Philosophy of Nature in which a hundred teachers-researchers from several intellectual and geographical horizons participate. It was founded in 2008 by Miguel Espinoza, from the University of Strasbourg. Among the problems discussed are the following: the continuity of science to metaphysics, the relationship between mathematics and the sensory world, naturalism, the different classes of causality in science and their relations with determinism and freedom, as well as the problem of understanding the natural hierarchy and the links between its different strata (physical, chemical, biological, psychic and social). These topics have been extensively discussed so far in six congresses held in Paris (twice), Mexico City, Temuco (Chile), Malaga and Bogota, whose proceedings have been published in several collective volumes: Eikasía, Revista de Filosofía, 27 ( 2009); 35 (2010); 43 (2012); 54 (2014); and since 2014 in Scripta Philosophiæ Naturalis.
(Parmenides: Head from a herm discovered at an excavation in Velia. )
The question of Nature is posed by the presocratic philosophers from the angle of the question of being. Parmenides (late 6th century, mid-5th century BC) is the key figure in this approach. He wrote a treatise on nature (Of nature), which is practically the only one we have preserved. Parmenides’ famous statement, posing a paralyzing truth for the mind: “Being is, non-being is not” posits Nature as ontologically intangible and eternal. In fact, non-being can not, by definition, be, how can the being to be from what is not? A more expressive reformulation can be: how can there be something from nothingness? This ontological affirmation, based on a fundamental logical truth, nevertheless poses the difficulty of the apprehension of Nature that we have through experience: it is in fact governed by change, birth and death, and therefore by the passage of a being to non-being.
The thought of Heraclitus is the extreme opposite of Parmenides’ elitism. For the latter, the unity of being makes impossible the deduction of becoming and multiplicity; for Heraclitus, on the contrary, being is eternally in the making. Heraclitus thus denies Parmenidian being. Things have no consistency, and everything moves unceasingly: nothing remains what it is, and everything goes to its opposite.
“To those who descend into the same rivers always come others and other waters.”
– Fragment 12, Arius Didyme in Eusebius, Evangelical Preparation, XV, 20, 2
Everything becomes everything, everything is everything. What lives dies, what is dead becomes alive: the current of generation and death never stops. What is visible becomes invisible, what is invisible becomes visible; day and night are one and the same thing; there is no difference between what is useful and what is harmful; the top does not differ from the bottom, the beginning does not differ from the end.
Plato devotes his dialogue The Sophist to refute Parmenides’ thesis, and to demonstrate the coexistence of being and non-being by introducing the concepts of movement, rest, and so on:
“The Stranger: It follows therefore necessarily that non-being is in motion and in all kinds; for in all, the nature of being, by rendering every other than being, makes it a non-being, so that from this point of view we can rightly say that they are all non-beings. and, on the other hand, because they participate in being, that they are and have being.”
A difficulty, nevertheless, remains for a Platonic approach of Nature: it is fundamentally a philosophy of Ideas, which poses the problem of the knowledge of Nature in terms of knowledge of the Idea of Nature. So, where Parmenides operates an ontological reductionism of Nature but inadequate to the understanding of diversity and observable changes, Plato requires us to see beyond what our senses offer us, and thus detaches us from Nature apprehended in the materiality.
(Portrait bust of Aristotle; an Imperial Roman (1st or 2nd century AD) copy of a lost bronze sculpture made by Lysippos. )
The conciliation of these two approaches (the positioning in the sensible world and the consideration of the change inherent in Nature) is made by Aristotle in Physics. This work, presented by Heidegger as “the fundamental book of Western philosophy”, initiates the metaphysical approach to Nature. Indeed, the knowledge of Nature for Aristotle consists in knowing not the elements (like Parmenides or physicists: water, earth, fire and air) but the first principles: the root causes. In this it is indeed a metaphysics because the method consists of starting from what is first for us, the sensible given and the totalities which are offered to us, to discover what is first by nature, it is to go beyond the knowledge of nature as it is given to us by trying to determine its foundations.
Nature is a way of being
Aristotle dedicates Chapters 2 and 3 of Book I to the criticism of the philosophers of the School of Elea, the Eleate, among whom is Parmenides. Chapter 2 begins thus: “to examine if the being is one and immobile, it is not to examine the nature”. It continues with the problematization of the concepts of being and of one: everyone can understand each other in different ways. The direct criticism made of Parmenides comes in Chapter 3. Aristotle reproaches Parmenides for conceiving of being only as a totality, neglecting that being can also be said of what composes this totality. Here we see the problem of the ratio of the components of this totality. Nature can now be apprehended as a mode of being, as a particular type of being.
Nature, a finality
Nature for Aristotle is more form than matter.
This great philosopher of the classical Greek epoch has written many treatises on nature, which retain some interest. The tradition of knowledge which, in the time of medieval scholasticism, was based on Aristotle and so-called first (or metaphysical) philosophy, whereas at the beginning, metaphysics was the second meta philosophy meaning in Greek after, was decried by Descartes, and especially Locke and the positivists, who criticized Scholasticism for not taking sufficient account of astronomical observations on the movement of planets. Nevertheless, Aristotle’s philosophy (and not his treatises on metaphysics in which the earth is at the center of the universe) certainly includes many interesting concepts today: for example, it does not limit logic to pure deduction, but includes other forms such as induction.
Francis Bacon (1561-1626)
This philosopher (not to be confused with Roger Bacon) is at the origin of proposals for a much more curious and practical approach to the study of nature. The classical and general conception of logic is based primarily on Aristotle’s Organum, and the new emphasis on induction and research is based on Francis Bacon’s Novum Organum.
Francis Bacon pursued a career in law and politics, and contributed to many fields of knowledge: science, philosophy, history and literature. He opposed scholasticism at a time when it was declining. He is considered the father of empiricism and the modern experimental method. He writes in the Novum Organum that knowledge comes to us as objects of nature, but that we impose our own interpretations on these objects. According to Bacon, our scientific theories are constructed according to the way we see objects; the human being is thus biased in his declaration of hypotheses. On the other hand, Bacon attributes precisely to the scientific activity a particular characteristic: the use of the number (“We can not recommend too much not to advance anything in natural history, that it is about the bodies or the virtues, which is not (as far as possible) numbered, weighed, measured, determined, for these are the works we have in view, and not the speculations, but physics and mathematics, well integrated into each other, engendering the practice”).
Robert Boyle (1627-1691)
He wrote what is considered a landmark work on the distinction between nature and metaphysics, called A Free Inquiry into the Vulgarly Received Notion of Nature. This book, written in 1686, marked the beginning of the transformation of natural philosophy into science. It represented a radical demarcation from the scholasticism of his time, in decline at the time of Galileo. While features of natural philosophy held some of the interests of the elite attached to his prerogatives, Boyle considered that it was sustainable to consider natural philosophy as empirical, since previous attempts to describe nature were unfounded. An important feature that distinguishes science and natural philosophy is the fact that natural philosophers of that time did not feel compelled to compare their ideas with practice. On the contrary, they observed the phenomena and deduced from them philosophical conclusions.