In logic, a consistent theory is one that does not contain a contradiction.^[1] The lack of contradiction can be defined in either semantic or syntactic terms. The semantic definition states that a theory is consistent if and only if it has a model, i.e. there exists an interpretation under which all formulas in the theory are true. This is the sense used in traditional Aristotelian logic, although in contemporary mathematical logic the term satisfiable is used instead. The syntactic definition states that a theory is consistent if and only if there is no formula P such that both P and its negation are provable from the axioms of the theory under its associated deductive system.

If these semantic and syntactic definitions are equivalent for a particular logic, the logic is complete.^{[clarification needed][citation needed]} The completeness of sentential calculus was proved by Paul Bernays in 1918^{[citation needed][2]} and Emil Post in 1921,^[3] while the completeness of predicate calculus was proved by Kurt Gödel in 1930,^[4] and consistency proofs for arithmetics restricted with respect to the induction axiom schema were proved by Ackermann (1924), von Neumann (1927) and Herbrand (1931).^[5] Stronger logics, such as second-order logic, are not complete.

A consistency proof is a mathematical proof that a particular theory is consistent. The early development of mathematical proof theory was driven by the desire to provide finitary consistency proofs for all of mathematics as part of Hilbert's program. Hilbert's program was strongly impacted by incompleteness theorems, which showed that sufficiently strong proof theories cannot prove their own consistency (provided that they are in fact consistent).

Although consistency can be proved by means of model theory, it is often done in a purely syntactical way, without any need to reference some model of the logic. The cut-elimination (or equivalently the normalization of the underlying calculus if there is one) implies the consistency of the calculus: since there is obviously no cut-free proof of falsity, there is no contradiction in general.

Consistency and completeness in arithmetic[link]

In theories of arithmetic, such as Peano arithmetic, there is an intricate relationship between the consistency of the theory and its completeness. A theory is complete if, for every formula φ in its language, at least one of φ or ¬ φ is a logical consequence of the theory.

Presburger arithmetic is an axiom system for the natural numbers under addition. It is both consistent and complete.

Gödel's incompleteness theorems show that any sufficiently strong effective theory of arithmetic cannot be both complete and consistent. Gödel's theorem applies to the theories of Peano arithmetic (PA) and Primitive recursive arithmetic (PRA), but not to Presburger arithmetic.

Moreover, Gödel's second incompleteness theorem shows that the consistency of sufficiently strong effective theories of arithmetic can be tested in a particular way. Such a theory is consistent if and only if it does not prove a particular sentence, called the Gödel sentence of the theory, which is a formalized statement of the claim that the theory is indeed consistent. Thus the consistency of a sufficiently strong, effective, consistent theory of arithmetic can never be proven in that system itself. The same result is true for effective theories that can describe a strong enough fragment of arithmetic – including set theories such as Zermelo–Fraenkel set theory. These set theories cannot prove their own Gödel sentences – provided that they are consistent, which is generally believed.

Formulas[link]

A set of formulas Failed to parse (Missing texvc executable; please see math/README to configure.): \Phi

in first-order logic is consistent (written ConFailed to parse (Missing texvc executable; please see math/README to configure.): \Phi

) if and only if there is no formula Failed to parse (Missing texvc executable; please see math/README to configure.): \phi

such that Failed to parse (Missing texvc executable; please see math/README to configure.): \Phi \vdash \phi
and Failed to parse (Missing texvc executable; please see math/README to configure.): \Phi \vdash \lnot\phi

. Otherwise Failed to parse (Missing texvc executable; please see math/README to configure.): \Phi

is inconsistent and is written IncFailed to parse (Missing texvc executable; please see math/README to configure.): \Phi

.

Failed to parse (Missing texvc executable; please see math/README to configure.): \Phi

is said to be simply consistent if and only if for no formula Failed to parse (Missing texvc executable; please see math/README to configure.): \phi
of Failed to parse (Missing texvc executable; please see math/README to configure.): \Phi

, both Failed to parse (Missing texvc executable; please see math/README to configure.): \phi

and the negation of Failed to parse (Missing texvc executable; please see math/README to configure.): \phi
are theorems of Failed to parse (Missing texvc executable; please see math/README to configure.): \Phi

.

Failed to parse (Missing texvc executable; please see math/README to configure.): \Phi

is said to be absolutely consistent or Post consistent if and only if at least one formula of Failed to parse (Missing texvc executable; please see math/README to configure.): \Phi
is not a theorem of Failed to parse (Missing texvc executable; please see math/README to configure.): \Phi

.

Failed to parse (Missing texvc executable; please see math/README to configure.): \Phi

is said to be maximally consistent if and only if for every formula Failed to parse (Missing texvc executable; please see math/README to configure.): \phi

, if Con (Failed to parse (Missing texvc executable; please see math/README to configure.): \Phi \cup \phi ) then Failed to parse (Missing texvc executable; please see math/README to configure.): \phi \in \Phi .

Failed to parse (Missing texvc executable; please see math/README to configure.): \Phi

is said to contain witnesses if and only if for every formula of the form Failed to parse (Missing texvc executable; please see math/README to configure.): \exists x \phi
there exists a term Failed to parse (Missing texvc executable; please see math/README to configure.): t
such that Failed to parse (Missing texvc executable; please see math/README to configure.): (\exists x \phi \to \phi {t \over x}) \in \Phi

. See First-order logic.

Basic results[link]

1. The following are equivalent:
   1. IncFailed to parse (Missing texvc executable; please see math/README to configure.): \Phi

1. 1. For all Failed to parse (Missing texvc executable; please see math/README to configure.): \phi,\; \Phi \vdash \phi.

1. Every satisfiable set of formulas is consistent, where a set of formulas Failed to parse (Missing texvc executable; please see math/README to configure.): \Phi

is satisfiable if and only if there exists a model Failed to parse (Missing texvc executable; please see math/README to configure.): \mathfrak{I}
such that Failed to parse (Missing texvc executable; please see math/README to configure.): \mathfrak{I} \vDash \Phi 

.

1. For all Failed to parse (Missing texvc executable; please see math/README to configure.): \Phi

and Failed to parse (Missing texvc executable; please see math/README to configure.): \phi

1. 1. if not Failed to parse (Missing texvc executable; please see math/README to configure.): \Phi \vdash \phi

, then ConFailed to parse (Missing texvc executable; please see math/README to configure.): \Phi \cup \{\lnot\phi\}

1. 1. if Con Failed to parse (Missing texvc executable; please see math/README to configure.): \Phi

and Failed to parse (Missing texvc executable; please see math/README to configure.): \Phi \vdash \phi

, then ConFailed to parse (Missing texvc executable; please see math/README to configure.): \Phi \cup \{\phi\}

1. 1. if Con Failed to parse (Missing texvc executable; please see math/README to configure.): \Phi

, then ConFailed to parse (Missing texvc executable; please see math/README to configure.): \Phi \cup \{\phi\}

or ConFailed to parse (Missing texvc executable; please see math/README to configure.):  \Phi \cup \{\lnot \phi\}

.

1. Let Failed to parse (Missing texvc executable; please see math/README to configure.): \Phi

be a maximally consistent set of formulas and contain witnesses.  For all Failed to parse (Missing texvc executable; please see math/README to configure.): \phi
and Failed to parse (Missing texvc executable; please see math/README to configure.):  \psi 

1. 1. if Failed to parse (Missing texvc executable; please see math/README to configure.): \Phi \vdash \phi

, then Failed to parse (Missing texvc executable; please see math/README to configure.): \phi \in \Phi ,

1. 1. either Failed to parse (Missing texvc executable; please see math/README to configure.): \phi \in \Phi

or Failed to parse (Missing texvc executable; please see math/README to configure.): \lnot \phi \in \Phi

,

1. 1. Failed to parse (Missing texvc executable; please see math/README to configure.): (\phi \or \psi) \in \Phi

if and only if Failed to parse (Missing texvc executable; please see math/README to configure.): \phi \in \Phi
or Failed to parse (Missing texvc executable; please see math/README to configure.): \psi \in \Phi

,

1. 1. if Failed to parse (Missing texvc executable; please see math/README to configure.): (\phi\to\psi) \in \Phi

and Failed to parse (Missing texvc executable; please see math/README to configure.): \phi \in \Phi 

, then Failed to parse (Missing texvc executable; please see math/README to configure.): \psi \in \Phi ,

1. 1. Failed to parse (Missing texvc executable; please see math/README to configure.): \exists x \phi \in \Phi

if and only if there is a term Failed to parse (Missing texvc executable; please see math/README to configure.): t
such that Failed to parse (Missing texvc executable; please see math/README to configure.): \phi{t \over x}\in\Phi

.

Henkin's theorem[link]

Let Failed to parse (Missing texvc executable; please see math/README to configure.): \Phi

be a maximally consistent set of Failed to parse (Missing texvc executable; please see math/README to configure.): S

-formulas containing witnesses.

Define a binary relation Failed to parse (Missing texvc executable; please see math/README to configure.): \sim

on the set of Failed to parse (Missing texvc executable; please see math/README to configure.): S

-terms such that Failed to parse (Missing texvc executable; please see math/README to configure.): t_0 \sim t_1

if and only if Failed to parse (Missing texvc executable; please see math/README to configure.): \; t_0 \equiv t_1 \in \Phi

and let Failed to parse (Missing texvc executable; please see math/README to configure.): \overline t \!

denote the equivalence class of terms containing Failed to parse (Missing texvc executable; please see math/README to configure.): t \!

and let Failed to parse (Missing texvc executable; please see math/README to configure.): T_{\Phi} := \{ \; \overline t \; |\; t \in T^S \}

where Failed to parse (Missing texvc executable; please see math/README to configure.): T^S \!
is the set of terms based on the symbol set Failed to parse (Missing texvc executable; please see math/README to configure.): S \!

.

Define the Failed to parse (Missing texvc executable; please see math/README to configure.): S -structure Failed to parse (Missing texvc executable; please see math/README to configure.): \mathfrak T_{\Phi}

over Failed to parse (Missing texvc executable; please see math/README to configure.):  T_{\Phi} \!
the term-structure corresponding to Failed to parse (Missing texvc executable; please see math/README to configure.): \Phi
by:

1. for Failed to parse (Missing texvc executable; please see math/README to configure.): n

-ary Failed to parse (Missing texvc executable; please see math/README to configure.): R \in S , Failed to parse (Missing texvc executable; please see math/README to configure.): R^{\mathfrak T_{\Phi}} \overline {t_0} \ldots \overline {t_{n-1}}

if and only if Failed to parse (Missing texvc executable; please see math/README to configure.): \; R t_0 \ldots t_{n-1} \in \Phi

1. for Failed to parse (Missing texvc executable; please see math/README to configure.): n

-ary Failed to parse (Missing texvc executable; please see math/README to configure.): f \in S , Failed to parse (Missing texvc executable; please see math/README to configure.): f^{\mathfrak T_{\Phi}} (\overline {t_0} \ldots \overline {t_{n-1}}) := \overline {f t_0 \ldots t_{n-1}}

1. for Failed to parse (Missing texvc executable; please see math/README to configure.): c \in S

, Failed to parse (Missing texvc executable; please see math/README to configure.): c^{\mathfrak T_{\Phi}}:= \overline c .

Let Failed to parse (Missing texvc executable; please see math/README to configure.): \mathfrak I_{\Phi} := (\mathfrak T_{\Phi},\beta_{\Phi})

be the term interpretation associated with Failed to parse (Missing texvc executable; please see math/README to configure.): \Phi

, where Failed to parse (Missing texvc executable; please see math/README to configure.): \beta _{\Phi} (x) := \bar x .

if and only if Failed to parse (Missing texvc executable; please see math/README to configure.):  \; \phi \in \Phi

Sketch of proof[link]

There are several things to verify. First, that Failed to parse (Missing texvc executable; please see math/README to configure.): \sim

is an equivalence relation.  Then, it needs to be verified that (1), (2), and (3) are well defined.  This falls out of the fact that Failed to parse (Missing texvc executable; please see math/README to configure.): \sim
is an equivalence relation and also requires a proof that (1) and (2) are independent of the choice of Failed to parse (Missing texvc executable; please see math/README to configure.):  t_0, \ldots ,t_{n-1} 
class representatives.  Finally, Failed to parse (Missing texvc executable; please see math/README to configure.):  \mathfrak I_{\Phi} \vDash \Phi 
can be verified by induction on formulas.

See also[link]

Logic portal

Wikiquote has a collection of quotations related to: Consistency

• Equiconsistency
• Hilbert's problems
• Hilbert's second problem
• Jan Łukasiewicz
• Matiyasevich's theorem
• ω-consistency

Footnotes[link]

1. ^ Tarski 1946 states it this way: "A deductive theory is called CONSISTENT or NON-CONTRADICTORY if no two asserted statements of this theory contradict each other, or in other words, if of any two contradictory sentences . . . at least one cannot be proved," (p. 135) where Tarski defines contradictory as follows: "With the help of the word not one forms the NEGATION of any sentence; two sentences, of which the first is a negation of the second, are called CONTRADICTORY SENTENCES" (p. 20). This definition requires a notion of "proof". Gödel in his 1931 defines the notion this way: "The class of provable formulas is defined to be the smallest class of formulas that contains the axioms and is closed under the relation "immediate consequence", i.e. formula c of a and b is defined as an immediate consequence in terms of modus ponens or substitution; cf Gödel 1931 van Heijenoort 1967:601. Tarski defines "proof" informally as "statements follow one another in a definite order according to certain principles . . . and accompanied by considerations intended to establish their validity[true conclusion for all true premises -- Reichenbach 1947:68]" cf Tarski 1946:3. Kleene 1952 defines the notion with respect to either an induction or as to paraphrase) a finite sequence of formulas such that each formula in the sequence is either an axiom or an "immediate consequence" of the preceding formulas; "A proof is said to be a proof of its last formula, and this formula is said to be (formally) provable or be a (formal) theorem" cf Kleene 1952:83.
2. ^ van Heijenoort 1967:265 states that Bernays determined the independence of the axioms of Principia Mathematica, a result not published until 1926, but he says nothing about Bernays proving their consistency.
3. ^ Post proves both consistency and completeness of the propositional calculus of PM, cf van Heijenoort's commentary and Post's 1931 Introduction to a general theory of elementary propositons in van Heijenoort 1967:264ff. Also Tarski 1946:134ff.
4. ^ cf van Heijenoort's commentary and Gödel's 1930 The completeness of the axioms of the functional calculus of logic in van Heijenoort 1967:582ff
5. ^ cf van Heijenoort's commentary and Herbrand's 1930 On the consistency of arithmetic in van Heijenoort 1967:618ff.

References[link]

• Stephen Kleene, 1952 10th impression 1991, Introduction to Metamathematics, North-Holland Publishing Company, Amsterday, New York, ISBN 0-7204-2103-9.
• Hans Reichenbach, 1947, Elements of Symbolic Logic, Dover Publications, Inc. New York, ISBN 0-486-24004-5,
• Alfred Tarski, 1946, Introduction to Logic and to the Methodology of Deductive Sciences, Second Edition, Dover Publications, Inc., New York, ISBN 0-486-28462-X.
• Jean van Heijenoort, 1967, From Frege to Gödel: A Source Book in Mathematical Logic, Harvard University Press, Cambridge, MA, ISBN 0-674-32449-8 (pbk.)
• The Cambridge Dictionary of Philosophy, consistency
• H.D. Ebbinghaus, J. Flum, W. Thomas, Mathematical Logic
• Jevons, W.S., 1870, Elementary Lessons in Logic

Ari Hest
Ari Hest performing at The Saint in Asbury Park, NJ, May 11, 2011
Background information
Born	(1979-06-16) June 16, 1979 (age 33) Mt. Sinai Hospital.Manhattan, NY, U.S.[1]
Genres	Rock, Acoustic, Pop
Occupations	Singer Musician
Instruments	Vocalist Guitarist Keyboardist Harmonicist Percussionist
Years active	1999–present
Labels	Columbia Records (2004-2007) Project 4 Records (1999-2004; 2007-Present)
Website	http://www.arihest.com

Ari Hest is an American singer-songwriter and a native of Riverdale^[1] in the Bronx borough of New York.

Biography[link]

Early life[link]

The Ari Hest performing in Doylestown

Ari took piano lessons as a child and later, as a teenager, taught himself to play his mother's nylon string guitar by ear with influences from both his parents' record collection and radio artists. Artists cited as influences are Paul Simon, The Beatles, Dave Matthews, U2, Smashing Pumpkins, Tears for Fears, The Police, Nirvana, and Pearl Jam among others. As a child, Ari aspired to become a professional baseball player and continued to play through the end of high school. During Ari's childhood, his father wrote jingles for toy commercials on television for which he sometimes recruited Ari to sing. One jingle noted by Ari as an example was a commercial for a girl's toy puppy from Hasbro branded "Sweetie Pups". Although he did not win, Ari competed in a Battle of the Bands contest in 11th grade playing Pearl Jam's "Nothing Man" and Led Zeppelin's "Thank You" with another young musician. Ari wrote his first song in 1996 that was titled "Surrounded By Surprise" and is defined by Ari as "something involving a made-up girlfriend and a hot-air balloon".^[1] Ari began playing in his first band called Synapse between 1997 and 1999.^[1] The band played venues such as New York City clubs and graduation parties. Ari's songs "Fade" and "Consistency" were born from this group.^[1] Ari attended Cornell University in Ithaca, NY beginning in 1999 and later transferred to New York University, where he received a degree in Communications in 2002.

Career[link]

Hest performing at The Saint in Asbury Park, NJ

While attending NYU, Ari began to focus on his musical career by touring colleges and clubs across the United States. Under his own independent recording label, Project 4, Ari released one EP, Incomplete and two albums, Come Home and Story After Story, selling approximately 20,000 CDs. In March 2004, Hest signed a recording contract with Columbia. He recorded his first studio album Someone To Tell with producer David Kos Rolfe, which was followed by a five-song EP "Guilty Hearts EP" in the fall of 2005. His sixth album, The Green Room Sessions, was recorded on a laptop personal computer using Apple's GarageBand software. Ari performed all vocals and instruments to include acoustic guitar, electric guitar, bass guitar, keyboards, harmonica, and percussion for this album. Ari sometimes gives demonstrations of GarageBand at Apple Stores that are both free and open to the public.^[2] Ari has completed the recording of his seventh album, The Break-In with producer Mitchell Froom. A single from the album I've Got You was released on Apple's iTunes in January 2007 and the full-length album was released by Columbia in May of that year. After leaving Columbia in 2008, Ari embarked on an ambitious project he called "52". For the entire year of 2008, Ari wrote, recorded and released a new song every week for 52 weeks and sent them via email to subscribers who paid a one time fee to receive all 52 songs throughout the year. The project was extremely successful, garnering Hest much praise in the media and from fans. In 2009, he released Twelve Mondays, a collection of 12 fan-selected songs reworked and rerecorded. It was self-released on Ari's Project 4 Records. In 2010, Ari went back into the studio to record his next album with producer Alex Wong. The result was Sunset Over Hope Street, released on March 1, 2011.

Family[link]

Ari's father plays a number of different horn instruments and is a college music professor. When Ari was a child, his father wrote jingles for children's toy commercials. His mother is currently a cantor. Ari's older brother, Daniel Hest, managed Ari for several years but now attends business school to receive his MBA.^[3]

Television & Radio Appearances[link]

Television[link]

• New York, NY, WPIX-TV 11 Morning News. Monday, August 9, 2004 at 8:45am EST. Live acoustic performance.
• CNNfn "The Biz". Tuesday, August 10, 2004 at 12:30pm EST. Interview.
• Chicago, IL, WGN-TV 9, Wednesday, September 8, 2004. Musical guest. Live performance and interview.
• "Last Call with Carson Daly". September 24, 2004.^[4] The episode also featured Jim Breuer, Bill Bellamy, Paul Rodriguez and No Use for a Name. Live performances of "They're On To Me" and "A Fond Farewell" from the album "Someone To Tell". This was Ari's network television debut.
• ESPN "Cold Pizza". Tuesday, October 26, 2004. Live performance.
• Philadelphia, PA, WCAU 10, Tuesday, December 2, 2004 at 9:30am EST.
• CBS "Saturday Early Show, Second Cup Cafe". January 1, 2005 at 7:00am EST. Live Performance.
• Kansas City, KS, WDAF-TV 4's "the Noon News", Tuesday, March 29, 2005 at 12:40pm EST. Live performance and interview.
• Austin, TX, KTBC 7, Tuesday, May 17, 2005 at 12:00pm EST. Live performance and interview.

Radio[link]

• Multiple radio stations. Acoustic Café, August 23, 2004. Recorded performance.
• WXPN Experimental Pennsylvania Network (88.5 FM) at the University of Pennsylvania in Philadelphia, PA. World Cafe, August 25, 2004 at 2:00pm EST. Live performance and interview with David Dye.
• XM Cafe (45 XM), "Build Your Own Show". September 6, 8th-10th, 2004. Live performance at XM Studios w/ Rob Calder.
• KMTT The Mountain (103.7FM) in Seattle, WA. January 19, 2005. Live performance at the Mountain Music Lounge.
• WRLT Radio Lightning, (100.1 FM) in Nashville, TN. Thursday, March 10, 2005. Live performance.
• WFUV Fordham University's Voice (90.7 FM) in New York, NY. Sunday, March 13, 2005. Live performance and interview on Pete Fornatale's "Mixed Bag".
• WBOS Boston (92.9 FM) in Boston, MA. Saturday, April 30, 2005. Live performance for the 12th Annual 92.9 WBOS EarthFest at Boston's Hatch Shell. Headliner: The Wallflowers. Other artists: Low Millions, Carbon Leaf, Five for Fighting.
• WBOS Boston (92.9 FM) in Boston, MA. Saturday, July 14, 2005. Live performance at the Copley Square Concert at 7:15pm EST.
• WBOS Boston (92.9 FM) in Boston, MA. Saturday, January 6, 2007. Live performance and interview from Bretton Woods Mountain Resort Slopeside Pub in Bretton Woods, NH.
• The Acoustic Lounge on KSFS podcast in San Francisco, CA. Released on June 20, 2007. Live performance of the May 13th, 2007 Bottom of the Hill concert and interview.

Music videos[link]

Hest performing at the Highline Ballroom in New York City, December 26, 2009

A small budget music video was recorded of the single "They're On To Me" featuring Ari moving through several New York cityscapes and playing a sold-out album release concert at New York City's Bowery Ballroom venue on August 10, 2004. The video was directed by Steven Oritt.

On March 22, 2008, Ari performed a live, interactive concert for his fans at DeepRockDrive. Songs performed include "Sleep Tonight", "Anne Marie", and "I've Got You".

Ari's video for So Slow was shot in Northport, Long Island and Washington Square Park in New York City.

Ari's video for "Dead End Driving" was shot in Phoenix, AZ and directed by Josh Franer

Band members[link]

Current[link]

Rob Calder • Bassist[link]

Often tours with Ari and can be seen in the 'making of' video on the "Guilty Hearts EP" disc as well as in the music video for "They're On To Me". In addition to working with Ari, Rob has performed and/or recorded with Angus & Julia Stone, Declan O'Rourke (on "Mag Pai Zai"), Paul Kelley/Angus Stone, John Southworth, Fiction Plane, Michael Brunnock, Findlay Brown, Will Stratton, Pete & J/Harper Blynn, Cutters, Kanye West, The Break & Repair Method, Colin Smith and Ghostface Killah to name a few.

Doug Yowell • Drummer[link]

Thad DeBrock • Guitarist[link]

Former[link]

Scott Seiver • Drummer[link]

Matt Beck • Guitarist[link]

A-Team[link]

The A-Team is a grassroots group of individuals who promote Ari's music with postcards, posters and through word of mouth. Additionally, members of the team are encouraged to record his live shows, publicly distribute them free of charge, and send a copy of the recording to Ari's website to be distributed over the internet via mp3 audio and videos. Perks for A-Team members include contests with prizes, access to the rep-only website, private rep concerts and exclusive media content.

Covers[link]

Ari covered Fleetwood Mac's "Little Lies" on his album The Green Room Sessions. Ari has covered "I'm On Fire" by Bruce Springsteen, Leonard Cohen's "Hallelujah", Radiohead's "No Surprises", Jeff Buckley's "Morning Theft", The Doobie Brothers' "What a Fool Believes" and Elton John's "Daniel" among many others during live performances.

Management[link]

Ari has been managed by his brother throughout his career. He is now managed by Brick Wall Management and is booked by Fleming Artists.

Discography[link]

Hest performing in Asbury Park, NJ, May 11, 2011

Full-Length, Extended Play and Single Albums[link]

• Incomplete (EP, 1999), Project 4 Records
• Come Home (2001), Project 4 Records
• Story After Story (2002). Project 4 Records
• Someone To Tell (2004), Columbia Records
• Guilty Hearts (EP, 2005), Columbia Records
• The Green Room Sessions (EP, 2006), Columbia Records
• I've Got You (Download only single, 2007), Columbia Records/Red Ink
• The Break-In (2007), Columbia Records/Red Ink
• Live at the Quick Center (EP, 2008), Project 4 Records
• 52 (2008), Project 4 Records
• Twelve Mondays (2009), Project 4 Records
• Sunset Over Hope Street (2011), Releasing on March 1, 2011, Project 4 Records

Promotional, Soundtrack and Other Albums[link]

• Consistency, Live From The Village Underground (2002), Project 4 Records, included with first 1,000 copies of “Story After Story”
• Winter Break: The Movie Soundtrack (2003), Various Artists, with “Strangers Again” from Ari Hest
• DecentXposure • Volume One (2003). Various Artists, with “Consistency” from Ari Hest
• "The Lincoln Lawyer" Soundtrack (2011) Various Artists, with "Now" from Ari Hest.

References[link]

5. ^ Ari Hest at On Campus Booking Ari Hest Live at The Roxy on May 26, 2005. Accessed on 02/10/2007.
Ari Hest News. Accessed on February 10, 2007.
Ari Hest Profile/Biography. Accessed on January 31, 2007.
Ari Hest Biography. Accessed on January 31, 2007.
Ari Hest Biography. Accessed on January 31, 2007.
About Ari - General Background. Accessed on February 5, 2007.

External links[link]

• Official Ari Hest website
• Ari Hest on the Live Music Archive
• Brick Wall Management: Ari Hest's management
• Ari Hest Fans
• The Ari Hest Show Archive
• Album Review: Ari Hest - Someone To Tell.
• Album Review: Ari Hest - Someone to Tell.
• Ari Hest Interview at StereoSubversion.com
• Ari Hest Interview with Sound Bites Dog E-Zine