A priori and a posteriori

a prioria posterioriA priori'' and ''a posterioria priori knowledgea priori proofa priori'' knowledgea-prioriapriorismaprioritya posteriori'' knowledge
The Latin phrases a priori ('from the earlier') and a posteriori ('from the later') are philosophical terms popularized by Immanuel Kant's Critique of Pure Reason (first published in 1781, second edition in 1787), one of the most influential works in the history of philosophy.wikipedia
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Dianetics: The Modern Science of Mental Health

DianeticsA.D.Book One
The very manner of "scientific method" displayed by Hubbard in his works has indeed been called "anti-science," in that the claims made in the books are based not on peer-reviewed observation of phenomena, with its attendant blind testing, control groups etc., but rather on deciding a priori that a phenomenon exists–followed by an attempt to prove its validity.


A posteriori necessity

a posteriori necessitiesa posteriori'' necessitiesA posteriori'' necessity
A posteriori necessity is a thesis in metaphysics and the philosophy of language, that some statements of which we must acquire knowledge a posteriori are also necessarily true.

Theory of everything (philosophy)

Theory of EverythingPhilosophical theory of everything
In the early modern period (17th and 18th centuries), the system-building scope of philosophy is often linked to the rationalist method of philosophy, that is the technique of deducing the nature of the world by pure a priori reason.

Natural rights and legal rights

natural rightslegal rightsnatural right
The existence of natural rights has been asserted by different individuals on different premises, such as a priori philosophical reasoning or religious principles.

Law (principle)

lawlawseconomic laws
Laws of mathematics and logic describe the nature of rational thought and inference (Kant's transcendental idealism, and differently G. Spencer-Brown's work Laws of Form, was precisely a determination of the a priori laws governing human thought before any interaction whatsoever with experience).

Forward start option

forward starting
Since the asset price at the start of this option is not known a priori, it is common to specify that the strike price will be set in the future so that the option is initially at the money or a certain percentage in the money or out of the money.

Skeptical movement

scientific skepticismskepticscientific skeptic
Scientific skeptics do not assert that unusual claims should be automatically rejected out of hand on a priori grounds—rather they argue that claims of paranormal or anomalous phenomena should be critically examined and that extraordinary claims would require extraordinary evidence in their favor before they could be accepted as having validity.

Field experiment

field experimentsfield trialsfield
Using field experiments as benchmarks can help determine levels of bias in observational studies, and, since researchers often develop a hypothesis from an a priori judgment, benchmarks can help to add credibility to a study.


PalestinianPalestinian ArabPalestinian people
By assigning its pursuit to the desire to predate Jewish national claims, he describes Canaanism as a "losing ideology", whether or not it is factual, "when used to manage our conflict with the Zionist movement" since Canaanism "concedes a priori the central thesis of Zionism. Namely that we have been engaged in a perennial conflict with Zionism—and hence with the Jewish presence in Palestine—since the Kingdom of Solomon and before ... thus in one stroke Canaanism cancels the assumption that Zionism is a European movement, propelled by modern European contingencies..."

David Harvey

Harvey, DavidDave HarveyDavid W. Harvey
He has never returned to embrace the arguments made in Explanation, but still he conforms to the critique of absolute space and exceptionalism in geography of the regional-historical tradition that he saw as an outcome of Kantian synthetic a priori knowledge.

The Mismeasure of Man

Gould alleged that much of the research was based largely on racial and social prejudices of the researchers rather than their scientific objectivity; that on occasion, researchers such as Samuel George Morton (1799–1851), Louis Agassiz (1807–1873), and Paul Broca (1824–1880), committed the methodological fallacy of allowing their personal a priori expectations to influence their conclusions and analytical reasoning.

Signorini problem

The statement of the problem involves not only equalities but also inequalities, and it is not a priori known what of the two sets of boundary conditions is satisfied at each point.

Samuel Clarke

ClarkeClarkeandr. Clarke
The former is not a purely a priori argument, and it was not presented as such.

Buddhist philosophy

BuddhistBuddhist philosophiesBuddhist thought
Another possible reason why the Buddha refused to engage in metaphysics is that he saw ultimate reality and nirvana as devoid of sensory mediation and conception and therefore language itself is a priori inadequate to explain it.

Philosophy of mathematics

mathematical realismmathematical Platonismmathematics
(This view bears resemblances to many things Husserl said about mathematics, and supports Kant's idea that mathematics is synthetic a priori.) Davis and Hersh have suggested in their 1999 book The Mathematical Experience that most mathematicians act as though they are Platonists, even though, if pressed to defend the position carefully, they may retreat to formalism.

Categorical imperative

CategoricalKant's Categorical Imperativecategorical freedom
Such judgments must be reached a priori, using pure practical reason.

Episode 2 (Twin Peaks)

Episode 22Episode 2" (''Twin Peaks'')
Academic readings of the episode have highlighted its depiction of heuristic, a priori knowledge, and the sexual undertones of several characters' actions.

Cultural relativism

cultural relativistcultural relativitymethodological relativism
All of our experiences of the world are mediated through the human mind, which universally structures perceptions according to a priori concepts of time and space.

Jessica Wilson

Her research focuses on metaphysics, especially on the metaphysics of science and mind, the epistemologies of skepticism, a priori deliberation, and necessity.


Pragmatists criticized the former for its a priorism, and the latter because it takes correspondence as an unanalyzable fact.


Antiphilosophy is anti-theoretical, critical of a priori justifications, and

Sociology of knowledge

phenomenological sociology of knowledgeknowledgesociological perspective
He argued, for example, that the categories of space and time were not a priori.


microeconomicmicroeconomic theoryprice theory
Mainstream economics does not assume a priori that markets are preferable to other forms of social organization.


pseudoarchaeologicalalternative archaeologypseudo-archaeology
In many cases, an a priori conclusion is established, and fieldwork is undertaken explicitly to corroborate the theory in detail.