
A principle may relate to a fundamental truth or proposition that serves as the foundation for a system of beliefs or behavior or a chain of reasoning.
They provide a guide for behavior or evaluation.
A principle can make values explicit, so they are expressed in the form of rules and standards. Principles unpack the values underlying them more concretely so that the values can be more easily operationalized in policy statements and actions.
In
law, higher order, overarching principles establish
rules
Rule or ruling may refer to:
Human activity
* The exercise of political or personal control by someone with authority or power
* Business rule, a rule pertaining to the structure or behavior internal to a business
* School rule, a rule tha ...
to be followed, modified by sentencing guidelines relating to context and proportionality. In science and nature, a principle may define the essential characteristics of the system, or reflect the system's designed purpose. The effective operation would be impossible if any one of the principles was to be ignored. A system may be explicitly based on and implemented from a document of principles as was done in IBM's
360/370 ''Principles of Operation''. It is important to differentiate an operational principle, including reference to 'first principles' from higher order 'guiding' or 'exemplary' principles, such as equality, justice and sustainability. Higher-order, 'superordinate' principles (Super-Ps) provide a basis for resolving differences and building agreement/alignment.
Examples of principles are,
entropy in a number of fields, least action in physics, those in descriptive comprehensive and fundamental law:
doctrine
Doctrine (from , meaning 'teaching, instruction') is a codification (law), codification of beliefs or a body of teacher, teachings or instructions, taught principles or positions, as the essence of teachings in a given branch of knowledge or in a ...
s or assumptions forming normative rules of conduct,
separation of church and state
The separation of church and state is a philosophical and Jurisprudence, jurisprudential concept for defining political distance in the relationship between religious organizations and the State (polity), state. Conceptually, the term refers to ...
in statecraft, the
central dogma of molecular biology,
fairness in ethics, etc.
In common English, it is a substantive and collective term referring to rule governance, the absence of which, being "unprincipled", is considered a character defect. It may also be used to declare that a reality has diverged from some ideal or norm as when something is said to be true only "in principle" but not in fact.
As law
As moral law

A principle represents values that orient and rule the conduct of persons in a particular society. To "act on principle" is to act in accordance with one's moral ideals. Principles are absorbed in childhood through a process of
socialization
In sociology, socialization (also socialisation – see American and British English spelling differences#-ise, -ize (-isation, -ization), spelling differences) is the process of Internalisation (sociology), internalizing the Norm (social), norm ...
. There is a presumption of liberty of individuals that is restrained. Exemplary principles include
First, do no harm, the
Golden Rule and the ''
Doctrine of the Mean''.
As a juridic law
It represents a set of values that inspire the written norms that organize the life of a society submitting to the powers of an authority, generally the State. The law establishes a legal obligation, in a coercive way; it therefore acts as principle
conditioning of the action that limits the liberty of the individuals. See, for examples, the
territorial principle,
homestead principle, and
precautionary principle.
As scientific law
Archimedes' principle, relating buoyancy to the weight of displaced water, is an early example of a
law in science. Another early one developed by
Malthus is the ''population principle'', now called the
Malthusian principle. Freud also wrote on principles, especially the
reality principle necessary to keep the id and
pleasure principle in check. Biologists use the
principle of priority and
principle of Binominal nomenclature for precision in naming
species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
. There are many principles observed in physics, notably in
cosmology
Cosmology () is a branch of physics and metaphysics dealing with the nature of the universe, the cosmos. The term ''cosmology'' was first used in English in 1656 in Thomas Blount's ''Glossographia'', with the meaning of "a speaking of the wo ...
which observes the
mediocrity principle, the
anthropic principle, the
principle of relativity and the
cosmological principle. Other well-known principles include the
uncertainty principle
The uncertainty principle, also known as Heisenberg's indeterminacy principle, is a fundamental concept in quantum mechanics. It states that there is a limit to the precision with which certain pairs of physical properties, such as position a ...
in
quantum mechanics
Quantum mechanics is the fundamental physical Scientific theory, theory that describes the behavior of matter and of light; its unusual characteristics typically occur at and below the scale of atoms. Reprinted, Addison-Wesley, 1989, It is ...
and the
pigeonhole principle and
superposition principle
The superposition principle, also known as superposition property, states that, for all linear systems, the net response caused by two or more stimuli is the sum of the responses that would have been caused by each stimulus individually. So th ...
in mathematics.
As axiom or logical fundament
Principle of sufficient reason
The principle states that every event has a rational explanation. The principle has a variety of expressions, all of which are perhaps best summarized by the following:
:For every entity ''x'', if ''x'' exists, then there is a sufficient explanation for why ''x'' exists.
:For every event ''e'', if ''e'' occurs, then there is a sufficient explanation for why ''e'' occurs.
:For every proposition ''p'', if ''p'' is true, then there is a sufficient explanation for why ''p'' is true.
However, one realizes that in every sentence there is a direct relation between the predicate and the subject. To say that "the Earth is round", corresponds to a direct relation between the subject and the predicate.
Principle of non-contradiction

According to
Aristotle
Aristotle (; 384–322 BC) was an Ancient Greek philosophy, Ancient Greek philosopher and polymath. His writings cover a broad range of subjects spanning the natural sciences, philosophy, linguistics, economics, politics, psychology, a ...
, "It is impossible for the same thing to belong and not to belong at the same time to the same thing and in the same respect." For example, it is not possible that in exactly the same moment and place, it rains and does not rain.
Principle of excluded middle
The principle of the excluding third or "principium tertium exclusum" is a principle of the traditional logic formulated canonically by
Leibniz as: either ''A'' is ''B'' or ''A'' isn't ''B''. It is read the following way: either ''P'' is true, or its denial ¬''P'' is.
It is also known as "''tertium non datur''" ('A third (thing) is not'). Classically it is considered to be one of the most important fundamental principles or laws of thought (along with the principles of identity, non-contradiction and sufficient reason).
See also
*
Ahimsa
(, IAST: , ) is the ancient Indian principle of nonviolence which applies to actions towards all living beings. It is a key virtue in Indian religions like Jainism, Buddhism and Hinduism.
(also spelled Ahinsa) is one of the cardinal vi ...
*
Axiom
An axiom, postulate, or assumption is a statement that is taken to be true, to serve as a premise or starting point for further reasoning and arguments. The word comes from the Ancient Greek word (), meaning 'that which is thought worthy or ...
*
Corollary
*
Deduction
*
Logical consequence
Logical consequence (also entailment or logical implication) is a fundamental concept in logic which describes the relationship between statement (logic), statements that hold true when one statement logically ''follows from'' one or more stat ...
*
Maxim (philosophy)
*
Non-aggression principle
*
Self-evidence
References
External links
*
*
''Actus Essendi'' and the Habit of the First Principle in Thomas Aquinas (New York: Einsiedler Press, 2019)
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{{Authority control
Concepts in epistemology
Concepts in ethics
Concepts in metaphysics
Concepts in the philosophy of mind
Concepts in the philosophy of science
Metaphysics of mind
Ontology