A Cartesian Diversion

    Descartes walks into a bar.
    Barman: "Pint of your usual?"
    Descartes: "I think not"
    <disappears>

    Thank you for telling me about Descartes.  I intend to put him into one of
    my Corklicks.  "What, in Gawd' Holy Name are Corklicks?", I hear you ask.
    Welllllll, Limericks were supposedly invented by a guy from Limerick.  Me,
    being from Cork, (and where else would I be from - sure isn't a cork de top
    o' de bottle?), I compose Corklicks.  I'll send you on one about Des when I
    get round to writing it.

And he did so here it is:

    Descartes walkes [sic] into a bar
    With "Methinks I might have me a jar
    And again I might not
    For I don't give a jot."
    Then disappears somewhere quite far.