this form of "calculemus" is printed in:
Die philosophischen Schriften von Gottfried Wilhelm Leibniz
(ed. C. J. Gerhardt), Volume 7, Berlin, 1890, p. 200 in a group of
texts [Vorarbeiten zur allgemeinen Charakteristik], title by
Gerhardt:
"... quando orientur controversiae, non magis disputatione opus erit
inter duos philosophos, quam inter duos Computistas. Sufficiet enim
calamos in manus sumere sedereque ad abacos, et sibi mutuo (accito si
placet amico) dicere: c a l c u l e m u s."
Similar expressions occur in other texts printed in the same volume
pp. 64-65 and 125.
There is also a letter to Philipp Jakob SPENER, Hannover, 8/18 July
1687, printed in: Gottfried Wilhelm Leibniz, S"amtliche Schriften und
Briefe: Reihe I: Allgemeiner, politischer und historischer
Briefwechsel, Volume 4: 1684-1687, Berlin/Leipzig, 1950, letter N.
538, p. 642:
"... omnia tamen superat consilium, qvod diu agito, omnes humanas
ratiocinationes ad calculum aliqvem characteristicum qvalis in
Algebra combinatoriave arte et numeris habetur, revocandi, qvo non
tantum certa arte inventio humana promoveri posset, sed et
controversiae multae tolli, certum ab incerto distingvi, et ipsi
gradus probabilitatum aestimari, dum disputantium alter alteri dicere
posset: calculemus."
With best regards
Siegmund Probst
> From: "L. M. Picard" <lmpicard@netcom.ca>
> Subject: Re: [HM] Leibniz's "let us calculate"?
> To: historia-matematica@chasque.apc.org
> Date: 17 Jul 99 17:55:24 -0400 (EDT)
> I have been searching for the most widely quoted of form of "Let us
> calculate". Leibniz is said to have written this in Dissertio de Arte
> Combinatoria, 1666:
>
> If controversies were to arise, "there would be no more need of
> disputation between two philosophers than between two accountants.
> For it would suffice to take their pencils in their hands, and say
> to each other: Let us calculate."
>
> L. M. Picard