First Principles – A Brief History
First principles in Ancient Greece
The concept of first principles goes back all the way to the first known philosophers in the Western world, who lived in Ancient Greece around 700-500 B.C. They are referred to as the Pre-Socratic philosophers and they sought to explain all of nature by finding the underlying origin of everything in the universe. They called this the “first principle” (or “arche” in Ancient Greek). The philosopher Thales of Miletus (c. 624 – c. 545 BC), the first known philosopher in Western philosophy, thought that the first principle was water. He believed that all things come from water and later go back to being water, and so this was the fundamental substance of the universe from which everything originated.1 Another Pre-Socratic philosopher, Anaximenes, believed that air was the first principle.2 His reasoning was based on the observations that water could appear from air through condensation.3 He concluded that everything in the universe must ultimately be air, and that substances only differ in regards to how dense the air is. For example, stone consists of air that is maximally dense, while fire consists of air that is the least dense.
The theories of the Pre-Socratic philosophers varied greatly.4 For example, Anaxagoras said that there were an infinite number of first principles or substances, and bone, flesh and marrow were some examples of such principles. Democritus also believed there were an infinite number of first principles but he thought of these as small, indivisible solids he called “atoms” which could be combined in different ways to create all things in the universe. Pythagoras and his followers, on the other hand, believed that numbers were the first principles, and everything in the world was created from different ratios of numbers.
So the theories were many, but the theory that eventually gained most popularity was that of Empedocles (c. 494 – c. 434 BC). He said that there were four first principles or elements: earth, water, air and fire. He believed that all things in the universe were made from a combination of these elements, and that there were two forces that caused elements to combine and to separate from each other. This theory came to be widely accepted in the Western world, and was the dominant view all the way to the 1600’s, more than 2000 years later. The person responsible for this was probably the philosopher Aristotle.
Aristotle’s systematic work on first principles
After the Pre-Socratic period of Western philosophy came the Classical period, and the view of first principles had a paradigm shift thanks to the philosopher Aristotle (384 – 322 BC). Instead of simply proposing his own view on what he thought were the first principles of the universe, he did a systematic analysis of what “first principles” actually means in order to understand this concept at a deeper level. Firstly, he noted that the word “first principle” (or “arche” – the original word in Ancient Greek) could have slightly different meanings depending on context. So he listed several different meanings of the word “first principle” (or “arche”) to get a better understanding of what it really is about.5 He showed, for example, that it may mean the thing from which something comes into being (e.g. a fire comes from a spark), or the deliberate choice from which an action is performed. After going through the list, he concluded that “first principle” is most properly defined as “the first basis from which something either exists or comes to be known”.
Secondly, Aristotle did a thorough analysis of all previous theories of first principles and analyzed both what they had in common and how they differed. He concluded that most theories concerned the first principles of matter, i.e. what fundamental substance or substances that all things are made of.6 Most of these theories also claimed that the substances could change or combine in different ways. Aristotle noted that because of this some philosophers had also become interested in how or why that occurred, and had tried to define forces responsible for this type of change.7 So he concluded that there were at least two different types of first principles: first principles of “matter”, which concern what the most fundamental substances are, and first principles of “motion”, which concern what the most fundamental laws or forces are that control how matter changes or moves. However, this distinction had not been clear to previous philosophers and their theories consequently were a bit confused.
In his further analysis, Aristotle concluded that we only truly know or understand something when we understand it from its first principles, and thus the primary task of science should be to find these principles.8 When some facts may be uncertain, first principles are always true.9
His thorough analysis of first principles set up a framework that could allow philosophers and scientists to be more successful in their endeavor to find truth, and would eventually inspire the birth of modern philosophy and science. Aside from discussing the nature of first principles more generally, Aristotle also provided his own take on what the first principles of the universe are, and in doing so, some claim that he became the world’s first physicist.
Aristotle based his physics on the ideas of Empedocles, with the four elements earth, water, air and fire, which he believed was the most accurate description of the fundamental nature of matter. He wanted to describe and explain how these different elements moved. He concluded that there were two different types of motion: natural motion and violent motion.10 Natural motion is how objects move without any assistance. The natural motion of earth and water are downwards. Earth wants to move towards the center of our planet. Water wants to move to the layer just above the earth’s surface. So that is where they will move unless something is stopping them. The natural motion of air and fire, on the other hand, is upwards. He also believed that the elements differed in how heavy they were, just like Anaximenes had reasoned. He concluded that the heavier an object is, the faster it will fall down, or for air and fire; the lighter an object is, the faster it will rise upwards. As for violent motion, this was the kind of motion that was not natural, and instead required something to force it to move in some way it didn’t want to. For example, if we wanted a stone to move sideways we would have to use force, and if we stopped applying this force, the stone would stop. In the Western world Aristotle’s physics was taught as fact for the next 2000 years. It was only in the 1600’s that philosophers and scientists began seriously questioning this view, and their work gave rise to modern science and philosophy.
The rise of modern science and philosophy
Galileo Galilei (15 February 1564 – 8 January 1642) and René Descartes (31 March 1596 – 11 February 1650) were contemporaries who both were interested in physics and hoped to show that Aristotle had been wrong on many counts. But they approached the subject from very different angles. Galileo was an Italian astronomer, physicist and engineer. He was a practical man who focused on making observations and drawing whatever conclusions he could from these. He had little interest in deeper philosophical questions, so he did not care for whether his conclusions were the first principles of the matter, or merely some practically useful principle. Although there were other scientists at the time who made carefully constructed experiments and performed exact observations, Galileo was the first one to use such methods to disprove fundamental Aristotelian ideas about how the world works. For example, Galileo let a ball roll down an incline and noted that it moved faster and faster. He then gave the ball a push up an incline and noted that it moved slower and slower (until it stopped and rolled back down). He reasoned that if the incline was made more and more horizontal, there must be some point where the ball neither increases its speed or decreases its speed, but simply continues at the same initial speed. He concluded that the only thing stopping the ball from rolling forever at the same speed on a horizontal surface, must be friction and air resistance.11 This directly contradicted Aristotle’s idea that objects that move sideways want to stop, and will do so as soon as no force is acting on them. Galileo also questioned Aristotle’s idea that heavier objects fall faster than lighter objects, and could similarly show that it was only due to air resistance that lighter objects sometimes appear to fall slower.12 If air resistance could be removed, all objects would fall at the same speed.
René Descartes was a French philosopher, mathematician and scientist. Contrary to Galileo, Descartes was not very interested in experiments and observations. He was more interested in theory, and believed that the important insights about philosophy and science could be achieved by thinking. Like Aristotle, he believed that the goal of philosophy and science is to find the first principles. He criticized Galileo for his lack of first principles, writing in a letter to a friend: “without having considered the first causes of nature, [Galileo] has merely looked for the explanations of a few particular effects, and he has thereby built without foundations.”13 Descartes believed it was necessary to go deeper to find more secure knowledge about the world. He said that if we could find the first principles, then all other facts about the world could be found by using logic, and we could be certain that our beliefs are correct.14 So Descartes took on this task, and the insights that Descartes arrived at would result in a second paradigm shift in the view of first principles.
Descartes went further than any previous philosopher in questioning ideas. While the philosophers before him had questioned certain common beliefs, they had also taken other beliefs for granted. But Descartes wondered whether it was possible that everything he believed was incorrect.15 Throughout his life he had on many occasions discovered that something he was certain to be true had actually turned out false. So he made a systematic analysis of whether it was possible to know anything with certainty. How could he prove that everything wasn’t just an illusion, or a dream? His famous discussion on the matter describes the idea of a little demon who could put all sorts of ideas in our heads and make us believe things that are completely untrue. If this were the case, could we ever figure that out and avoid being fooled, or alternatively, could there be something that it would be impossible for the demon to trick us into believing? Descartes came to the realization that the little demon could never trick us into falsely believing that we exist when in reality we don’t. For the demon to be able to trick us with anything, we must exist to begin with. Otherwise there is no one to trick. This further means that if we question whether we know anything at all, we must necessarily exist. Otherwise it wouldn’t be possible for us to question anything. “I think, therefore I exist”, or “Cogito, ergo sum”, is how he summarized this insight, and he concluded that this must be the first principle of philosophy. This truth must be the starting point for all philosophy and science since it is the first idea we can prove to be true if we decide to question all assumptions.
Part of what made Descartes views on first principles so groundbreaking was that it showed another domain where first principles could, or rather should, be applied: the mind. Previous first principles theories had only concerned the physical world, but Descartes pointed out that whenever we reason about the physical world we use beliefs and reasoning that are part of our mind, and we must first have a first principles understanding of our mind in order to trust our conclusions. From the principle of “Cogito, ergo sum” he then tried to deduce the rest of the principles concerning human knowledge, and after that, the principles of the material world (i.e. physics).16 This resulted in the book “Principles of philosophy” containing over 300 principles (depending on how you count), which according to Descartes all followed logically from the first principle of “Cogito, ergo sum”. No first principles project had ever before been so ambitious. Unfortunately, Descartes’ reasoning contained many flaws, and he failed to achieve the desired goal. All the same, his work would greatly influence science and philosophy for the centuries to come. Most notably, Descartes expanded on Galileo’s insight that a ball would roll forever on a horizontal surface if there was no friction or air resistance. Descartes further imagined that if there was also no gravity, the ball would even float in the air, and continue moving in a straight line in space unless something stopped it. This opened up the possibility to view the physical world in a very different way than before, where movement is determined by forces outside the objects, rather than drives within them. This is when Isaac Newton entered the stage, and changed the world forever.
Newton’s revolution
Isaac Newton (4 January 1943 – 31 March 1727) was an English mathematician, physicist, astronomer and alchemist. He took on the task to understand physics from the new perspective, and with his work came the third paradigm shift in first principles, and the creation of modern science. Newton himself said: “If I have seen further than others, it is by standing upon the shoulders of giants”. Galileo and Descartes were among these giants upon whose work Newton had built, but there were also others: some who had performed rigorous experiments and made interesting observations, some who had made advancements in mathematics. But even with these shoulders to stand on, Newton’s own advancements in both mathematics and physics were truly remarkable. In his book “Mathematical principles of natural philosophy”17 he laid out three simple first principles of motion, and from these he could explain and predict the motion of everything in the universe, including such vast phenomena as the motion of planets, the motion of projectiles, the motion of objects who collide, and motion of pendulums and springs. He called these principles “Laws of motion”, and they were as follows:
Law 1: An object at rest will remain at rest, and an object in motion will remain in motion unless it is acted upon by an external force.
Law 2: The change of motion (momentum) of an object is proportional to the force acted upon it, and is made in the direction of a straight line in which the force acts. (often expressed as F = ma in mathematical form)
Law 3: For every action, there is an equal and opposite reaction. Or put differently: If two objects exert forces on each other, these forces have the same magnitude but opposite directions.
Despite the complexity of the world, Newton showed that a few simple principles can be enough to understand the world at its core. What was also groundbreaking about his work was that he used mathematics to deduce the rest of the principles of motion, which meant that the solution to problems of physics could be calculated with great accuracy.
What has happened since Newton
Now that the world had seen the true power of first principles, the field of physics became focused on finding the first principles of all areas within the field, and expressing these as mathematical equations that could be used to perform exact calculations for the purposes of explaining and predicting all phenomena in the physical world. Over the next centuries, the first principles approach also spread to other topics, most notably chemistry and biology, and our understanding of the world deepened rapidly. For example, in 1859 the English biologist Charles Darwin released the book “On the origin of species”18 where he could explain the features of all species on earth through his theory of evolution, which in turn consisted of a simple first principle of natural selection. In 1869 the Russian chemist Dmitri Mendeleev published the book “Principles of Chemistry”19, where he presented a new way of understanding chemical elements. This consisted of the Periodic table of chemical elements, as well as the Periodic Law which made it possible to predict the properties of all chemical elements, depending on their place in the periodic table.
In some areas, however, the focus on first principles took a different turn. With the emergence of modern science, with its precise methods and powerful principles, science started to be called “science” instead of “natural philosophy”, which it had been called previously. And so the term “philosophy” instead came to denote the questions that were thought not to belong to science, for example, “What is knowledge?”, “What is reality?”, “What is the good life?”, “What is ethics?”, “What is art?”. Because of the abstract and complex nature of these questions, attempts to find the first principles in these topics failed again and again, and at the end of the 1900’s philosophers had generally given up on the idea that it was possible (or worthwhile) to find the first principles in areas of philosophy. Instead, philosophers now debate which theory has the most acceptable disadvantages, rather than which theory is the correct one. This is of course an inevitable effect of not having found the first principles of the philosophical questions. A survey in 200920 showed that there is disagreement on practically all philosophical questions, and prominent philosophers complain about the lack of progress, some merely saying there isn’t enough progress21, and others saying there hasn’t been any progress whatsoever since the Pre-Socratic philosophers.22
So at the present time, we have some fields of knowledge where first principles are seen as essential (like modern physics) and some areas where first principles are almost frowned upon (modern philosophy). There are also some fields where there is a certain ambivalence towards first principles, most notably the social sciences.
First principles in the social sciences
A common belief is that one of the major differences between natural sciences (physics, chemistry, biology, etc) and social sciences (psychology, sociology, economics, etc) is that only the natural sciences have first principles, or fundamental laws that are always true. Social sciences, on the other hand, are often believed to consist of a vast number of facts or theories that have no underlying fundamental laws. It is seen as natural that theories within social sciences often can seem contradictory, because what matters is to present different perspectives, not the one objective truth. But others within the field believe that finding a set of fundamental laws, or first principles, is desirable, even necessary for social sciences to make progress.
Let’s take psychology as an example. At the beginning of the 2000’s, the field had a crisis, called “the replication crisis”, when it turned out that many of the most notable psychological findings in the 1900’s were incorrect.23 The results of the experiments had merely been an effect of statistical chance. Psychologists had failed to suspect that the results were incorrect, because there was no unified theory of psychology that could be used to evaluate the results. But there have been a number of attempts at finding the first principles of psychology, with some degree of success. Most notably is that of behaviorism, which already from the early 1900’s attempted to explain all of psychology using two principles: classical conditioning and instrumental conditioning.24 In the last decade another attempt has gained popularity called predictive processing, which attempts to explain all of psychology using the principle of Bayesian prediction.25 The problem is that the different approaches to first principles seem to have nothing in common, or worse, even contradict each other in some cases.
As for sociology, since the 1960’s there have been a number of criticisms against sociology as a science, where some sociologists have claimed that it is impossible to study society using scientific methods, others have claimed that it is impossible to separate ideology from science in the study of sociology.26 There isn’t any consensus on neither facts nor methodology in sociology, and some even believe this is a good thing. Still, as in psychology, there have been a few attempts at finding the first principles of sociology, with some degree of success. Most notable is the work of Pierre Bourdieu, who advanced Field theory27, and the Theory of capital28, to explain what happens in social situations. But given the vastness of all that is included under the banner of “sociology”, no attempt has yet had the scope that would be required, and the disagreement within the field is as strong as ever.
So that is where we are right now, but things may be about to change.
Next: The Origins of A Wiser World
Page-ID: 6
This page is version 1.0. It has not yet been reviewed by the global community. Do you want to help improve it? Please leave a comment in the google document for this page, or join the email group to be part of the discussion. You can always share your thoughts via email directly to mail@awiserworld.net. Read more about how you can support A Wiser World.
References:
1. Aristotle – Metaphysics 983 b6 8–11. https://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.01.0052%3Abook%3D1%3Asection%3D983b
2. Aristotle – Metaphysics 984a
https://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.01.0052%3Abook%3D1%3Asection%3D984a
3. Dye, James (2014), “Anaximenes of Miletus”, Biographical Encyclopedia of Astronomers, Springer New York, pp. 74–75, doi:10.1007/978-1-4419-9917-7_49, ISBN 9781441999160
4. A description of all the following theories from the Pre-Socratic philosophers can be found in Aristotle’s Metaphysics. (see above)
5. Aristotle – Metaphysics – Book 5 1012b
6. Aristotle – Metaphysics 983 b6 8–11. https://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.01.0052%3Abook%3D1%3Asection%3D983b
Most of the earliest philosophers conceived only of material principles as underlying all things. That of which all things consist, from which they first come and into which on their destruction they are ultimately resolved, of which the essence persists although modified by its affections—this, they say, is an element and principle of existing things. Hence they believe that nothing is either generated or destroyed, since this kind of primary entity always persists.
7. Aristotle – Metaphysics 984a
https://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.01.0052%3Abook%3D1%3Asection%3D984a
From this account it might be supposed that the only cause is of the kind called “material.” But as men proceeded in this way, the very circumstances of the case led them on and compelled them to seek further; because if it is really true that all generation and destruction is out of some one entity or even more than one, why does this happen, and what is the cause? It is surely not the substrate itself which causes itself to change. I mean, e.g., that neither wood nor bronze is responsible for changing itself; wood does not make a bed, nor bronze a statue, but something else is the cause of the change. Now to investigate this is to investigate the second type of cause: the source of motion, as we should say.
8. Aristotle – Physics Book 1 part 1
When the objects of an inquiry, in any department, have principles, conditions, or elements, it is through acquaintance with these that knowledge, that is to say scientific knowledge, is attained. For we do not think that we know a thing until we are acquainted with its primary conditions or first principles, and have carried our analysis as far as its simplest elements. Plainly therefore in the science of Nature, as in other branches of study, our first task will be to try to determine what relates to its principles.
9. Aristotle – Metaphysics 993b
Therefore in every case the first principles of things must necessarily be true above everything else—since they are not merely sometimes true, nor is anything the cause of their existence, but they are the cause of the existence of other things,—and so as each thing is in respect of existence, so it is in respect of truth.
10. Aristotle – Physics Book 8
11. Galileo – Discourses and Mathematical Demonstrations Relating to Two New Sciences (1638)
12. Galileo – Discourses and Mathematical Demonstrations Relating to Two New Sciences (1638)
13. René Descartes, Oeuvres De Descartes, edited by Charles Adam and Paul Tannery (Paris: Librairie Philosophique J. Vrin, 1983), vol. 2, pp. 380. Descartes in a letter to his friend and critic Mersenne written in 1638.
14. René Descartes, The Philosophical Writings of Descartes: Principles of Philosophy, Preface to French Edition, translated by J. Cottingham, R. Stoothoff, D. Murdoch (Cambridge: Cambridge Univ. Pr., 1985), vol. 1, pp. 179–189.
Descartes in a letter written in 1647 to the translator of Principles of Philosophy:
“a perfect knowledge […] must necessarily be deduced from first causes […] we must try to deduce from these principles knowledge of the things which depend on them, that there be nothing in the whole chain of deductions deriving from them that is not perfectly manifest.”
15. The whole argument that follows can be found in René Descartes – Meditations on First Philosophy (1641)
16. René Descartes, Principles of philosophy, 1644
17. Often called “Principia” after the original latin name of this book: Philosophiæ Naturalis Principia Mathematica
18. Charles Darwin, The origin of species, 1859
19. Dmitri Mendeleev, Principles of Chemistry, 1869
20. See “Bourget & Chalmers (2014) What do philosophers believe?” for a presentation of the results found in the survey.
21. For example Chalmers, D. J. (2015). Why isn’t there more progress in philosophy?
22. See Dietrich, E. (2011). There is no progress in philosophy.
23. Ioannidis, J., (2005). Why most published research findings are false.
24. Skinner, B.F., 1938. The Behavior of Organisms.
25. See for example Clark, A. (2016) Surfing uncertainty. or Hohwy, J. (2013) The predictive mind.
26. See Balon & Holmwood, 2019, The impossibility of sociology as a science; arguments from within the discipline.
27. Bourdieu, 1977, Outline Of a Theory Of Practice.
28. Bourdieu, 1986, The Forms of Capital.