--- title: The 2 Types of Knowledge You Should Know About description: And how to figure out the difference between the two. canonical: https://time.com/4070788/planck-chauffeur-knowledge/ author: Shane Parrish article:opinion: true article:content_tier: free article:published_time: 2015-10-15T04:01:24.000Z article:modified_time: 2026-03-31T08:47:04.411Z article:section: Ideas og:title: The 2 Types of Knowledge You Should Know About og:description: And how to figure out the difference between the two og:url: https://time.com/4070788/planck-chauffeur-knowledge/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt4eb9e8e4e1c0d452/6988604c8e06017e23461fdb/brain-health-illo.jpg?branch=production&width=2400&quality=75&auto=webp&crop=16:9 og:image:width: 1200 og:image:height: 675 og:image:alt: TIME.com stock health brain og:type: article twitter:card: summary_large_image twitter:title: The 2 Types of Knowledge You Should Know About twitter:description: And how to figure out the difference between the two twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt4eb9e8e4e1c0d452/6988604c8e06017e23461fdb/brain-health-illo.jpg?branch=production&width=2400&quality=75&auto=webp&crop=16:9 ---  # The 2 Types of Knowledge You Should Know About ## Video: Do Brain Exercises Really Keep You Mentally Fit? [Watch (HLS stream): Do Brain Exercises Really Keep You Mentally Fit?](https://cdn.jwplayer.com/manifests/t67dFcgw.m3u8) (2:03)  _Published 2015-05-15. Do Brain Exercises Really Keep You Mentally Fit?_ by [Shane Parrish](/author/shane-parrish/) ## Shane Parrish Oct 15, 2015 4:01 AM CUT  Illustration by Sydney Rae Hass for TIME by [Shane Parrish](/author/shane-parrish/) ## Shane Parrish Oct 15, 2015 4:01 AM CUT In [_The Art of Thinking Clearly_](http://www.amazon.com/gp/product/0062219693/ref=as%5Fli%5Fqf%5Fsp%5Fasin%5Fil%5Ftl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0062219693&linkCode=as2&tag=farnamstreet-20&linkId=IUG5JIH4RHI3YSJL "undefined"), Rolf Dobelli tells the following story about Max Planck. --- > “” --- Charlie Munger, the billionaire business partner of Warren Buffett frequently tells this story in speeches. Why? He elaborates in a 2007 address to USC Law. The point of the story is not the quick wittedness of the protagonist, but rather – to [echo Richard Feynman](https://www.farnamstreetblog.com/2015/01/richard-feynman-knowing-something/ "undefined") – it’s about making a distinction between the two types of knowledge. --- > “” --- Real knowledge is when people [do the work](https://www.farnamstreetblog.com/2013/04/the-work-required-to-have-an-opinion/ "undefined"). This is so important that Elon Musk tries to [tease it out in interviews](https://www.farnamstreetblog.com/2015/05/elon-musk-lying-experience/ "undefined"). Then we have the people who don’t do the work. While they’ve learned to put on a good show they lack understanding. The problem is that it’s difficult to separate the two. One way to tease out the difference between Planck and chauffeur knowledge — is to [ask them why](https://www.farnamstreetblog.com/2014/06/winning-an-argument/ "undefined"). In [_The Art of Thinking Clearly_](http://www.amazon.com/gp/product/0062219693/ref=as%5Fli%5Fqf%5Fsp%5Fasin%5Fil%5Ftl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0062219693&linkCode=as2&tag=farnamstreet-20&linkId=IUG5JIH4RHI3YSJL "undefined") Dobelli goes on: --- > “” --- One way to guard against this is to [understand your circle of competence](https://www.farnamstreetblog.com/2013/12/mental-model-circle-of-competence/ "undefined"). Dobelli concludes: --- > “” --- **_This piece originally appeared on_** [**_Farnam Street_**](https://www.farnamstreetblog.com/2015/09/two-types-of-knowledge/ "undefined")**_._** **Join over 60,000 readers and get a free weekly update via email** [**here**](http://www.farnamstreetblog.com/newsletter/ "undefined")**.** ```json [{"@context":"https://schema.org","@type":"OpinionNewsArticle","@id":"https://time.com/4070788/planck-chauffeur-knowledge/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/4070788/planck-chauffeur-knowledge/"},"headline":"The 2 Types of Knowledge You Should Know About","datePublished":"2015-10-15T04:01:24.000Z","dateModified":"2026-03-31T08:47:04.411Z","description":"And how to figure out the difference between the two.","url":"https://time.com/4070788/planck-chauffeur-knowledge/","keywords":["Culture","Psychology","intelligence"],"thumbnailUrl":"https://static.time.com/v3/assets/bltea6093859af6183b/blt4eb9e8e4e1c0d452/6988604c8e06017e23461fdb/brain-health-illo.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","author":[{"@type":"Person","name":"Shane Parrish","jobTitle":"","url":"https://time.com/author/shane-parrish/"}],"articleSection":"Ideas","image":[{"@type":"ImageObject","url":"https://static.time.com/v3/assets/bltea6093859af6183b/blt4eb9e8e4e1c0d452/6988604c8e06017e23461fdb/brain-health-illo.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","width":1200,"height":675,"headline":"TIME.com stock health brain","caption":"TIME.com stock health brain","creditText":"Illustration by Sydney Rae Hass for TIME","representativeOfPage":true}],"publisher":{"@type":"Organization","name":"Time","url":"https://time.com/","logo":{"@type":"ImageObject","url":"https://time.com/images/logo.png","width":528,"height":156},"foundingDate":"March 3, 1923","sameAs":["https://www.facebook.com/time","https://www.instagram.com/time/?hl=en","https://twitter.com/time","https://www.pinterest.com/timemagazine"]}},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/section/ideas/","name":"Ideas"}},{"@type":"ListItem","position":2,"item":{"@id":"/tag/culture/","name":"Culture"}},{"@type":"ListItem","position":3,"item":{"@id":"https://time.com/4070788/planck-chauffeur-knowledge/","name":"The 2 Types of Knowledge You Should Know About"}}]},{"@context":"https://schema.org","@type":"VideoObject","name":"Do Brain Exercises Really Keep You Mentally Fit?","description":"Do Brain Exercises Really Keep You Mentally Fit?","thumbnailUrl":"https://cdn.jwplayer.com/v2/media/t67dFcgw/poster.jpg?width=720","uploadDate":"2015-05-15T21:17:02.000Z","contentUrl":"https://cdn.jwplayer.com/manifests/t67dFcgw.m3u8","embedUrl":"https://time.com/4070788/planck-chauffeur-knowledge/","duration":"PT2M3S","potentialAction":{"@type":"SeekToAction","target":"https://time.com/4070788/planck-chauffeur-knowledge/?jw_start={seek_to_second_number}","startOffset-input":"required name=seek_to_second_number"}}] ```