13 LEG 1 (2007)

handle is hein.journals/legthory13 and id is 1 raw text is: 

Legal Theory, 13 (2007), 1-22. Printed in the United States ofAmerica
Published by Cambridge University Press 0361-6843/07 $15.00 +00
DOI 10.1017.S1352325207070012


Oliver  Black
King's  College   London,   Linklaters

Philosophers have been attracted by the theory that an agreement consists of under-
takings by the parties. But the theory faces objections from three sides: unconditional
undertakings by both parties are insufficient for an agreement; if the parties give in-
terconditional undertakings, both comply if neither does anything; and, if one party
gives an unconditional undertaking and the other a conditional one, a condition of
interdependence is breached. The options are to live with the breach, to produce
an undertaking-based theory that avoids the objections, or to analyze an agreement
otherwise than in terms of undertakings. I consider each option and advocate the
third: a better theory is that two people have an agreement where one makes an offer
to the other that the other accepts.

If X undertakes  to Y that X will do Ax, and Y undertakes to X that Y will
do Ay, they do not thereby agree with each other that they will respectively
do  Ax and  Ay: there is just a pair of unconditional undertakings. Nor, it
seems,  is there an agreement  between  them  if each merely gives to the
other a conditional undertaking:  if, for example, X undertakes to Y that
if Y will do Ay X will do Ax, and Y undertakes  to X that if X will do Ax
Y will do Ay, it appears that both will comply with their undertakings  if
neither does  anything; but X  must do  Ax and  Y must  do Ay  if they are
to comply  with an agreement  to perform  those actions. If this is right, an
agreement  cannot  be generated by complicating  the conditionals, so that,
for example,  X undertakes  that if, if X will do Ax, Y will do Ay, X will do
Ax, andY  undertakes the converse; for, depending on interpretation, either
this is equivalent to two unconditional undertakings or both parties can still
comply  by doing nothing.
  Philosophers  have nevertheless been attracted by the idea that an agree-
ment  can be  modeled  in terms of undertakings  (a category that includes
promises) by the parties. In Agreements, Undertakings, and Practical Rea-
son I proposed two such models which  develop the thought that there is an
agreement  where  one party gives a conditional undertaking and the other
responds  with an unconditional  undertaking.1 Because  of this asymmetry

  1. 0. Black, Agreements, Undertakings, and Practical Reason, 10 LEGAL THEORY (2004), here-
inafter AUPR; the same line is taken in 0. BLACK, CONCEPTUAL FOUNDATIONS OF ANTITRUST
(2005), at ch. 4. Note 3 of the former cites other works in which it is held that art agreement
is to be understood in terms of undertakings.


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