Philosophy of motion
Philosophy of motion is a branch of philosophy concerned with exploring questions on the existence and nature of motion. The central questions of this study concern the epistemology and ontology of motion, whether motion exists as we perceive it, what is it, and, if it exists, how does it occur. The philosophy of motion is important in the study of theories of change in natural systems and is closely connected to studies of space and time in philosophy.
The philosophy of motion was of central concern to Ancient Greek and Roman philosophers, particularly the pre-Socratic philosophers such as Parmenides, Zeno of Elea, Heraclitus and Democritus. As such, it was influential in the development of the philosophy of science in general.
The Greek Physiologoi
The concept of motion is closely related to the idea of change, and it is arguments about what made change possible that led the early Greek philosophers to pioneer naturalistic explanations for phenomena.
Heraclitus had famously declared that "all is motion".
Parmenides professed that from our human point of view there are two aspects to the study of the universe of which we must be aware, on the one hand how we see it, and on the other how it must really be. Motion is a fact from our point of view, but Parmenides argues that as far as things must really be, it is logically impossible that motion could exist as we perceive it.
Zeno of Elea, a pupil of Parmenides, formulated the Arguments against motion, more commonly referred to as the paradoxes, in order to support his masters theories of the One and of the consequent impossibility of motion at the fundamental level. The rigorous denial of even the possibility of motion forced a more thorough response from philosophers engaged on the same theoretical project.
Atomism and Determinism
In response, Democritus expounded the atomic theory, in which indivisible bits of matter are in constant motion through the void. In the absence of something to perturb them they fall evenly through space.
Motion conceived in this way led naturally to questions of free will and determinism. In response to this, Epicurus appears to have included the concept of the clinamen, or atomic swerve. This tiny random motion serves to bring atoms into contact and begin the cascade that leads to the organisation of matter as we see it now., it also introduced an element of uncertainty which appears to have been an important concept in Epicurus' insistence on the existence of individual choice.
Aristotle, in his physics, defines motion as the actuality of a potentiality.
Further east, in China, the Sanlun school of Mahayana Buddhism developed a sophisticated philosophy of motion under the philosopher Sengzhao. His treatise called The Immutability of Things, deals with motion explicitly.
Aztec metaphysics gave priority to motion over substance in its cosmological ontology. In other words, process was seen to be fundamental and objects or substances as ephemeral. Change therefore was naturally conceived of as motion, and this motion was divided into three forms, out of which all change occurs. These were named olin (bouncing, oscillating) malinalli (spinning, twisting, spiralling) and, the most important, nepantla (weaving, intersecting, joining, balancing).
Achieving a coherent understanding of motion has been, and continues to be, of importance in understanding the nature of space and time in modern science. The main philosophical debate has been between absolute and relational conceptions of motion.
Motion in complex systems such as protein folding.
Morphogenesis of animal bodies and change on large and small scales. Niche construction.
The work of Nottale.
Questions of the nature of motion continue to arise in modern physics, with many of the issues of concern to early thinkers arising in different form. Heisenberg's uncertainty principle and the clinamen of the Epicureans.