In philosophy, "first principles" are from
first cause and later "first principle" or "element". By extension, it may mean "first place", "method of government", "empire, realm", or "authorities". The concept of an
arche was adapted from the earliest
cosmogonies of
Hesiod and
Orphism, through the physical theories of
Pre-Socratic philosophy and
Plato before being formalized as a part of
metaphysics by
Aristotle.
Arche, sometimes also transcribed as
arkhé, is an Ancient Greek word with primary senses "beginning", "origin" or "source of action", from the beginning, οr the original argument, "command". The first principle or element corresponds to the "ultimate underlying substance" and "ultimate indemonstrable principle".
Mythical cosmogonies The heritage of Greek
mythology already embodied the desire to articulate reality as a whole and this universalizing impulse was fundamental for the first projects of speculative theorizing. It appears that the order of "being" was first imaginatively visualized before it was abstractly thought. In the mythological cosmogonies of the Near East, the universe is formless and empty and the only existing thing prior to creation was the water abyss. In the
Babylonian creation story,
Enuma Elish, the primordial world is described as a "watery chaos" from which everything else appeared. This watery chaos has similarities in the cosmogony of the Greek mythographer
Pherecydes of Syros. In the mythical
Greek cosmogony of
Hesiod (8th to 7th century BC), the origin of the world is
Chaos, considered as a divine primordial condition, from which everything else appeared. In the creation "chaos" is a gaping-void, but later the word is used to describe the space between the Earth and the sky, after their separation. "Chaos" may mean infinite space, or a formless matter which can be differentiated. The notion of temporal infinity was familiar to the Greek mind from remote antiquity in the religious conception of immortality. The conception of the "divine" as an origin influenced the first Greek philosophers. In the
Orphic cosmogony, the unaging
Chronos produced
Aether and Chaos and made in divine Aether a silvery egg, from which everything else appeared.
Ionian school The earliest Pre-Socratic philosophers, the Ionian material monists, sought to explain all of nature (
physis) in terms of one unifying
arche. Among the material monists were the three Milesian philosophers:
Thales, who believed that everything was composed of water;
Anaximander, who believed it was
apeiron; and
Anaximenes, who believed it was air. This is considered as a permanent substance or either one or more which is conserved in the generation of rest of it. From this all things first come to be and into this they are resolved in a final state. This source of entity is always preserved. Although their theories were primitive, these philosophers were the first to give an explanation of the physical world without referencing the supernatural; this opened the way for much of modern
science (and philosophy), which has the same goal of explaining the world without dependence on the supernatural. Thales of Miletus (7th to 6th century BC), known as "the father of philosophy", claimed that the first principle of all things is water, and considered it as a substance that contains in it motion and change. His theory was supported by the observation of moisture throughout the world and coincided with his theory that the Earth floated on water. His ideas were influenced by the Near-Eastern mythological cosmogony and probably by the
Homeric statement that the surrounding
Oceanus (ocean) is the source of all springs and rivers. Anaximander argued that water could not be the arche, because it could not give rise to its opposite, fire. Anaximander claimed that none of the
elements (
earth,
fire,
air,
water) could be arche for the same reason. Instead, he proposed the existence of the
apeiron, an indefinite substance from which all things are born and to which all things will return.
Apeiron (endless or boundless) is something completely indefinite; and Anaximander was probably influenced by the original
chaos of Hesiod (yawning abyss). Anaximander was the first philosopher to use
arche for that which writers from Aristotle onwards called "the substratum" (
Simplicius Phys. 150, 22). He probably intended it to mean primarily "indefinite in kind" but assumed it also to be "of unlimited extent and duration". The notion of temporal infinity was familiar to the Greek mind from remote antiquity in the religious conception of immortality and Anaximander's description was in terms appropriate to this conception. This
arche is called "eternal and ageless". (Hippolitus I,6, I;DK B2) Anaximenes, Anaximander's pupil, advanced yet another theory. He returns to the elemental theory, but this time posits air, rather than water, as the arche and ascribes to it divine attributes. He was the first recorded philosopher who provided a theory of change and supported it with observation. Using two contrary processes of
rarefaction and
condensation (thinning or thickening), he explains how air is part of a series of changes. Rarefied air becomes fire, condensed it becomes first wind, then cloud, water, earth, and stone in order. The
arche is technically what underlies all of reality/appearances.
Aristotle Terence Irwin writes: Aristotle himself calls the
law of noncontradiction "the most certain of all principles" in
Metaphysics Book IV.
Modern philosophy Descartes Profoundly influenced by
Euclid,
Descartes was a
rationalist who invented the
foundationalist system of philosophy. He used the
method of doubt, now called
Cartesian doubt, to systematically doubt everything he could possibly doubt until he was left with what he saw as purely indubitable truths. Using these self-evident propositions as his axioms, or foundations, he went on to deduce his entire body of knowledge from them. The foundations are also called
a priori truths. His most famous proposition is "Je pense, donc je suis" (
I think, therefore I am, or
Cogito ergo sum), which he indicated in his
Discourse on the Method was "the first principle of the philosophy of which I was in search." Descartes describes the concept of a first principle in the following excerpt from the preface to the
Principles of Philosophy (1644): == In physics ==