De Motu: Sive, de Motus Principio & Natura, et de Causa Communicationis Motuum (On Motion: or The Principle and Nature of Motion and the Cause of the Communication of Motions), or simply De Motu, [1] is an essay written by George Berkeley and published as a tract in London in 1721. The essay was unsuccessfully submitted for a prize that had been offered by the Royal Academy of Sciences at Paris.
Berkeley rejected Sir Isaac Newton's absolute space, time and motion. With this essay, Berkeley is considered to be the "precursor of Mach and Einstein" (Karl Popper). [2] [3] [4]
We must pay attention to facts regarding things and their nature, not to words or to someone's authority. The mind should be concerned with particular and concrete things themselves, not with abstract terms. The effects that are felt on our senses should be noticed. The causes of these effects are rationally inferred and are occult qualities.
Gravity and force are examples of occult qualities. But they can be useful terms. Gravity can designate concrete bodies in motion and force can designate the concrete effort of resisting. However, they should not be used abstractly, separate from concrete, individual things. If no change occurs and there is no effect, then there is no force. Force, gravity, and attraction are mathematical, hypothetical abstractions and they are not found in nature as physical qualities. The parallelogram of composite forces is not a physical quality. It is mathematical. Attempts to explain the cause and origin of motion are abstract and obscure. They are not particular and determinate assertions. Such attempts try to explain the unknown by something that is even more unknown.
Bodies are not known to contain, within themselves, forces that cause motion. Minds, however, are known to cause motion. Such minds are particular, individual causes that are parts of the primary, universal cause of motion.
Bodies are passive, not active. They merely persist indifferently in their states, whether of impelled motion or of rest. Action and reaction are only mathematical hypotheses, not physical qualities. It is useful to refer to action and reaction when demonstrating mechanics, but they are not causes of motion.
We personally experience within ourselves a cause of our bodily motion. It is called soul, mind, or spirit. But, we do not experience a cause of motions inside of other bodies. The ultimate cause of the motion of all bodies is the mind of God. This is known through metaphysics and theology.
Natural science is limited to experiments and mechanics, but it assumes that God was the prime source of motion. The laws of motion, not the cause of motion, are established by natural science. Physicists explain and understand phenomena by showing how they agree with the laws of motion. Fictional, abstract, general terms such as force, action, and reaction are used in theories, formulas, and computations. These cannot be found in bodies. [5]
Through our senses, we actually experience only the effects of moving or resting bodies. The natural scientist is concerned with experiments, laws of motion, mechanical principles, and rational deduction from those principles. The principle and cause of motion itself is a metaphysical, theological, and moral concern.
Motion should not be considered as an abstraction, separated from space and time. It should not be analyzed into abstract ideas such as movement, velocity, and force. Mathematical considerations of spatial and temporal infinitesimals lead to paradoxes. Motion should not be equated with the cause of motion. To say that the quantity of motion is always conserved is to confuse motion itself with the force that causes motion. The force of the cause of motion is conserved. Motion is not an internal, living force in things. It is a lifeless, indifferent effect.
Absolute space contains no bodies. But, as such, it would not be observable. Nothing is denoted by the words "absolute space." Motion and space are relative. They presuppose a relationship to some other body through which they are determined. For a wider view, it would be useful to consider motion relative to the fixed stars, which would be considered as being at rest, instead of to absolute space. Just as we cannot know absolute space, we cannot know whether the whole universe is at rest or is moving uniformly in a direction.
To determine the true nature of motion, we must follow three rules: (1) distinguish mathematical hypotheses from the nature of things; (2) beware of abstractions; (3) consider motion as sensible or imaginable and be content with relative measures.
Physical science is concerned only with mechanics. Therefore, it can be said that, in a collision, action and reaction are always opposite and equal. Such actions and forces, though, are only mathematical hypotheses. We only really know that the striking body loses motion and the struck body gains motion. We do not know if the motion is communicated from one body to another or if the motion is destroyed in the striker and is created in the struck. In the true nature of things, all bodies are passive. The truly active cause of motion is metaphysical and not the concern of physical science.
Abstraction is a process wherein general rules and concepts are derived from the usage and classification of specific examples, literal signifiers, first principles, or other methods.
Isaac Newton's rotating bucket argument was designed to demonstrate that true rotational motion cannot be defined as the relative rotation of the body with respect to the immediately surrounding bodies. It is one of five arguments from the "properties, causes, and effects" of "true motion and rest" that support his contention that, in general, true motion and rest cannot be defined as special instances of motion or rest relative to other bodies, but instead can be defined only by reference to absolute space. Alternatively, these experiments provide an operational definition of what is meant by "absolute rotation", and do not pretend to address the question of "rotation relative to what?" General relativity dispenses with absolute space and with physics whose cause is external to the system, with the concept of geodesics of spacetime.
In ontology, the theory of categories concerns itself with the categories of being: the highest genera or kinds of entities according to Amie Thomasson. To investigate the categories of being, or simply categories, is to determine the most fundamental and the broadest classes of entities. A distinction between such categories, in making the categories or applying them, is called an ontological distinction. Various systems of categories have been proposed, they often include categories for substances, properties, relations, states of affairs or events. A representative question within the theory of categories might articulate itself, for example, in a query like, "Are universals prior to particulars?"
George Berkeley – known as Bishop Berkeley – was an Anglo-Irish philosopher whose primary achievement was the advancement of a theory he called "immaterialism". This theory denies the existence of material substance and instead contends that familiar objects like tables and chairs are ideas perceived by the mind and, as a result, cannot exist without being perceived. Berkeley is also known for his critique of abstraction, an important premise in his argument for immaterialism.
Idealism in philosophy, also known as philosophical idealism or metaphysical idealism, is the set of metaphysical perspectives asserting that, most fundamentally, reality is equivalent to mind, spirit, or consciousness; that reality is entirely a mental construct; or that ideas are the highest form of reality or have the greatest claim to being considered "real". The radical latter view is often first credited to the Ancient Greek philosopher Plato as part of a theory now known as Platonic idealism. Besides in Western philosophy, idealism also appears in some Indian philosophy, namely in Vedanta, one of the orthodox schools of Hindu philosophy, and in some streams of Buddhism.
In theoretical physics, particularly in discussions of gravitation theories, Mach's principle is the name given by Albert Einstein to an imprecise hypothesis often credited to the physicist and philosopher Ernst Mach. The hypothesis attempted to explain how rotating objects, such as gyroscopes and spinning celestial bodies, maintain a frame of reference.
In philosophy of science and in epistemology, instrumentalism is a methodological view that ideas are useful instruments, and that the worth of an idea is based on how effective it is in explaining and predicting natural phenomena. According to instrumentalists, a successful scientific theory reveals nothing known either true or false about nature's unobservable objects, properties or processes. Scientific theory is merely a tool whereby humans predict observations in a particular domain of nature by formulating laws, which state or summarize regularities, while theories themselves do not reveal supposedly hidden aspects of nature that somehow explain these laws. Instrumentalism is a perspective originally introduced by Pierre Duhem in 1906.
Philosophy of space and time is the branch of philosophy concerned with the issues surrounding the ontology and epistemology of space and time. While such ideas have been central to philosophy from its inception, the philosophy of space and time was both an inspiration for and a central aspect of early analytic philosophy. The subject focuses on a number of basic issues, including whether time and space exist independently of the mind, whether they exist independently of one another, what accounts for time's apparently unidirectional flow, whether times other than the present moment exist, and questions about the nature of identity.
Absolute space and time is a concept in physics and philosophy about the properties of the universe. In physics, absolute space and time may be a preferred frame.
A Treatise Concerning the Principles of Human Knowledge is a 1710 work, in English, by Irish Empiricist philosopher George Berkeley. This book largely seeks to refute the claims made by Berkeley's contemporary John Locke about the nature of human perception. Whilst, like all the Empiricist philosophers, both Locke and Berkeley agreed that we are having experiences, regardless of whether material objects exist, Berkeley sought to prove that the outside world is also composed solely of ideas. Berkeley did this by suggesting that "Ideas can only resemble Ideas" – the mental ideas that we possess can only resemble other ideas and thus the external world consists not of physical form, but rather of ideas. This world is given logic and regularity by some other force, which Berkeley concludes is God.
Ferdinand Canning Scott Schiller, FBA, usually cited as F. C. S. Schiller, was a German-British philosopher. Born in Altona, Holstein, Schiller studied at the University of Oxford, later was a professor there, after being invited back after a brief time at Cornell University. Later in his life he taught at the University of Southern California. In his lifetime he was well known as a philosopher; after his death, his work was largely forgotten.
The deductive-nomological model of scientific explanation, also known as Hempel's model, the Hempel–Oppenheim model, the Popper–Hempel model, or the covering law model, is a formal view of scientifically answering questions asking, "Why...?". The DN model poses scientific explanation as a deductive structure, one where truth of its premises entails truth of its conclusion, hinged on accurate prediction or postdiction of the phenomenon to be explained.
Prolegomena to Any Future Metaphysics That Will Be Able to Present Itself as a Science is a book by the German philosopher Immanuel Kant, published in 1783, two years after the first edition of his Critique of Pure Reason. One of Kant's shorter works, it contains a summary of the Critique‘s main conclusions, sometimes by arguments Kant had not used in the Critique. Kant characterizes his more accessible approach here as an "analytic" one, as opposed to the Critique‘s "synthetic" examination of successive faculties of the mind and their principles.
The General Scholium is an essay written by Isaac Newton, appended to his work of Philosophiæ Naturalis Principia Mathematica, known as the Principia. It was first published with the second (1713) edition of the Principia and reappeared with some additions and modifications on the third (1726) edition. It is best known for the "Hypotheses non fingo" expression, which Newton used as a response to some of the criticism received after the release of the first edition (1687). In the essay Newton not only counters the natural philosophy of René Descartes and Gottfried Leibniz, but also addresses issues of scientific methodology, theology, and metaphysics.
Metaphysics is the branch of philosophy that investigates principles of reality transcending those of any particular science. Cosmology and ontology are traditional branches of metaphysics. It is concerned with explaining the fundamental nature of being and the world. Someone who studies metaphysics can be called either a "metaphysician" or a "metaphysicist".
The following outline is provided as an overview of and topical guide to metaphysics:
In physics, the concept of absolute rotation—rotation independent of any external reference—is a topic of debate about relativity, cosmology, and the nature of physical laws.
In physics, the history of centrifugal and centripetal forces illustrates a long and complex evolution of thought about the nature of forces, relativity, and the nature of physical laws.
This is a glossary of terms used in New Thought.
Coleridge's theory of life is an attempt by Samuel Taylor Coleridge to understand not just inert or still nature, but also vital nature. He examines this topic most comprehensibly in his work Hints towards the Formation of a more Comprehensive Theory of Life (1818). The work is key to understand the relationship between Romantic literature and science.