Definition of principle in English:



  • 1A fundamental truth or proposition that serves as the foundation for a system of belief or behavior or for a chain of reasoning.

    ‘the basic principles of Christianity’
    • ‘There's sense here in going back to some of the basic principles of liberal political philosophy.’
    • ‘Although its application was inevitably uneven, the Code Napoléon was intended to serve as a universal set of principles founded on reason.’
    • ‘The evenly balanced scales of blind justice derive from this principle.’
    • ‘In this introductory article, we lay out some basic principles for understanding complex systems.’
    • ‘It is simply not possible to negotiate a political settlement with people who do not understand, or who refuse to accept, basic democratic principles.’
    • ‘In my tale, I set out the metaphysical principles, i.e. principles outside the closed system of the ethics being discussed, on which the ethics are based.’
    • ‘The basic principle for a democratic republic is the independence of the three branches of government executive, legislature and judiciary.’
    • ‘The challenge to their leadership is to have the courage to support basic democratic principles, only excluding those, who by their actions exclude themselves.’
    • ‘But it was only with the publication of Filangieri's great work that a comprehensive reformulation of the nature and underlying principles of the state and of society finally emerged.’
    • ‘The freedom to make a choice is the basic principle of our democratic world.’
    • ‘Draconian provisions which alter the principles and foundation of our legal system may serve in the long run to undermine that system and give rise to perfidies not initially contemplated.’
    • ‘The assumption is that these principles of justice underlie any conception of the good.’
    • ‘And yet, of course, our principles of fairness and justice must be upheld.’
    • ‘It is a fundamental principle in our system of justice that people are treated the same, regardless of their income or status in life, and it is important to uphold that.’
    • ‘It is a fraternal order whose basic principles are philanthropy, truth and brotherly love.’
    • ‘What are some of the basic principles and beliefs of Catholicism?’
    • ‘The principles of natural law gained ground, and accompanying them came a growing belief in the equality of all human beings.’
    • ‘One of the basic principles of a democratic, liberal country is the decentralization of power.’
    • ‘This is a foundation principle of western justice and a basic human right.’
    • ‘Following the enlightenment principle of truth through reason alone, it was thought that history cannot be determined until theology has been removed.’
    truth, proposition, concept, idea, theory, postulate
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    1. 1.1A rule or belief governing one's personal behavior.
      ‘struggling to be true to their own principles’
      [mass noun] ‘she resigned over a matter of principle’
      • ‘Law, in the sense of rules and principles that govern human conduct, is a blunt instrument.’
      • ‘But I'm going to speak directly from the heart based on the principles that I believe in.’
      • ‘Although some aspects of suicidal behaviour might be interpreted as rational, the behaviour is contrary to basic biological principles of survival.’
      • ‘Rarely have I encountered anyone as passionate and determined in his principles as Donald Bruce, a true patriot and a man who led a remarkable life.’
      • ‘If you can forsake your fundamental principles for any reason then you are not the kind of person who can take the country forward.’
      • ‘There are three key defining experiences in my life that form the foundation of my principles and beliefs.’
      • ‘Commonly, the codes will address certain principles, and these will be governed by written rules.’
      • ‘Doing what's right appears to be more of a concern for him than for the average person; his platform is strongly governed by his personal principles.’
      • ‘These principles have governed Snow's approach in growing the family business tenfold since he took the reins in the mid 1980s.’
      morals, morality, moral standards, moral values, ethics, code of ethics, beliefs, credo, ideals, standards, integrity, uprightness, high-mindedness, righteousness, virtue, probity, rectitude, sense of honour, honour, decency, conscience, sense of duty, scruples
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    2. 1.2Morally correct behavior and attitudes.
      ‘a man of principle’
      • ‘We worked out a position we could adhere to throughout the campaign, one based on principle as well as convenience.’
      • ‘To do so is foolish and ill-mannered, invites scorn, and is contrary to the whole principle of the clan system.’
      • ‘‘I want to bring principle and honour back into politics’ said Jim as he addressed the meeting.’
      • ‘Seinfeld exposes the human destructiveness and lack of principle and morality that exist to some degree in all people.’
      • ‘Prof Southall is a man of great principle and he won't change his mind if he does not think his mind should be changed.’
      • ‘As well as being wrong in principle, it is wrong in terms of club competition.’
      • ‘I admire and respect him for his repeated and unsung - even derided - demonstrations of integrity and principle.’
      • ‘Bafflingly, a knighthood still awaits, but this present accolade will surely not be the last that comes the way of a musician of unswerving integrity and principle.’
      • ‘For nothing indicates a failure to understand the nature of a moral principle better than to believe that it is capable of enforcing itself.’
      • ‘He should be a man of principles, a source of good.’
      • ‘However, you should not lose heart or compromise over an issue based on principle.’
      • ‘It seems that in situations such as this, politics become incompatible with conscience, principle, decency and self-respect.’
      • ‘How in one walk of life a person can have such a rigid sense of right and wrong - and in another he can operate with a total disregard for principle, integrity and fair play.’
      • ‘At six, he is too young to determine what his own principles are in this regard.’
      • ‘Therefore, ethical action is equated with following rules, principles, laws, maxims, and codes.’
      • ‘But he's clearly a man of principle and unbending honesty - who, at times, can be cruelly insensitive, as when he tells a man he has casually examined that he has a tumour.’
      • ‘However, in the attempt to unite, there must be no compromise of principle and professional integrity must reign supreme.’
      • ‘While people may be sceptical about politicians who moralise, they are anxious to see them display integrity and principle.’
      • ‘Money had replaced principles in determining policy.’
      • ‘Legislation based on principle and evidence will have our support.’
      morals, morality, moral standards, moral values, ethics, code of ethics, beliefs, credo, ideals, standards, integrity, uprightness, high-mindedness, righteousness, virtue, probity, rectitude, sense of honour, honour, decency, conscience, sense of duty, scruples
      View synonyms
    3. 1.3A general scientific theorem or law that has numerous special applications across a wide field.
      • ‘Engineering involves the application of scientific and mathematical principles.’
      • ‘One line of evidence for the holographic principle comes from black hole physics.’
      • ‘Accordingly, atomic physics relies on the principles of quantum mechanics to describe the discrete nature of matter at the atomic and subatomic levels.’
      • ‘Angular momentum, like all other forms of motion, follows the general principle stated in Newton's third law.’
      • ‘These connections allowed a broad dissemination not only of principles but especially the application of the methods of scientific management.’
      • ‘The uncertainty principle has been successfully used as a key eligibility criterion for large, simple trials.’
      • ‘Einstein believed that Maxwells theory should, like all other laws of nature obey the principle of relativity.’
      • ‘In 1748 Maupertuis showed that Newton's laws of motion could be derived by the application of a teleological principle.’
      • ‘A working understanding of basic mathematical principles is ideal, but mostly you just need a calculator and the desire to play the stocks and bonds game.’
      • ‘The application of scientific principles eventually leads to a fair evaluation of the benefits, disadvantages and true effects of every compound.’
      • ‘Quantum chemistry involves the application of the principles of quantum theory to chemistry.’
      • ‘Guitar pickups work by the principles of magnetic induction.’
      • ‘Physics has a big advantage here, since the ability to derive interesting conclusions from general principles comes earlier in physics than in other sciences.’
      • ‘Now the general principles on which quantum field theory are based actually allow for many different consistent theories to be constructed.’
      • ‘Simple physics principles might explain the mysterious magnetic fields that seem to permeate the cosmos.’
      • ‘A physical principle called the diffraction limit says that light cannot be used to see or inscribe features that are smaller than half its wavelength.’
      • ‘The code uses so called Bayesian networks, a combination of statistical principles, including Bayes Theorem, hence the name.’
      • ‘For example, there's a short film of Dr. Richard Feynman explaining a principle of quantum mechanics called Bell's inequality.’
      • ‘When Dirac developed the general principles of quantum theory, this democratic equality between different points of view was maintained in the new dynamics that resulted.’
      • ‘The Heisenberg uncertainty principle dictates that he can measure the bits in only one mode, not both.’
    4. 1.4A natural law forming the basis for the construction or working of a machine.
      ‘these machines all operate on the same general principle’
      • ‘However, back then, explanations that were given to the general public regarding the actual principle of the flying machine appeared to be quite vague.’
      • ‘He adopted a new basis for hydrostatics, using two principles from his mechanics, and explained for the first time how a heavy beam can be floated in very little water.’
      • ‘He might have used mechanical aids such as Alberti's veil, the various gadgets illustrated by Durer, or other machines following similar principles.’
      • ‘The principles underlying steam power, machine tools, and mass production were less familiar, hence less transparent.’
      • ‘Mbemba designed the machine around the mathematical principle of the sinuskurve, or sine wave.’
      • ‘Yet, that was the age of levers and pulleys, and machines based on mechanical principles were being used as analog computers in many different ways.’
  • 2A fundamental source or basis of something.

    ‘the first principle of all things was water’
    1. 2.1A fundamental quality or attribute determining the nature of something; an essence.
      ‘the combination of male and female principles’
      • ‘In this close relationship the artist occupies a pivotal position, since he is gifted with the ability to recognize divine principles in nature and recreate these in his works.’
      • ‘As sun and moon represent the male and female principles, once again we see the potential for a happy union between you.’
      • ‘Holding the rapt attention of the audience, the duo exemplified the concept of the male and female principles working in harmony and balance in the Universe, unique to Hindu mythology.’
      • ‘Keeping any part of the surplus is simply theft and thus violates the moral principle of justice.’
      • ‘Just as the male and female principles complement each other, our views of history also much combine to give a holistic view of the past.’
    2. 2.2Chemistry [with adjective]An active or characteristic constituent of a substance, obtained by simple analysis or separation.
      ‘the active principle in the medulla is epinephrine’
      • ‘Various studies on the active principles of the manchineel tree have shown tigliane phorbol esters to be the likely cause of the severe reactions.’
      • ‘The pungency of pepper is due to the active principles it contains - the volatile oil, piperine, and resin.’
      • ‘The active principle is extracted and purified from plant material for as long as that process remains economically viable compared with chemical synthesis.’
      • ‘The active principles were identified as baicalein from the first and methyl gallate from the last two plants.’
      • ‘The development of purified cardiac glycosides, the active principles of digitalis, has been a distinct step forward in the treatment of diseases of the heart.’


On the confusion of principle and principal, see principal


Late Middle English: from Old French, from Latin principium source principia (plural) foundations from princeps, princip- first, chief.