Performatives in a Rationally Based Speech Act 
Theory* 
Philip R. Cohen 
Artificial Intelligence Center 
and 
Center for the Study of Language and Information 
SRI International 
333 Ravenswood Ave. 
Menlo Park, CA 94025 
and 
Hector J. Levesque $ 
Department of Computer Science 
University of Toronto 
Abstract 1 Introduction 
A crucially important adequacy test of any the- 
ory of speech acts is its ability to handle perfor- 
matives. This paper provides a theory of perfor- 
matives as a test case for our rationally based the- 
ory of illocutionary acts. We show why "I request 
you..." is a request, and "I lie to you that p" is 
self-defeating. The analysis supports and extends 
earlier work of theorists such as Bach and Harnish 
\[1\] and takes issue with recent claims by Searle \[10\] 
that such performative-as-declarative analyses are 
doomed to failure. 
*This paper was made possible by a contract from 
ATR International to SRI International, by a gift from 
the Systems Development Foundation, and by a grant 
from the Natural Sciences and Engineering Research 
Council of Canada. The views and conclusions con- 
tained in this document axe those of the authors and 
should not be interpreted as representative of the of- 
ficial policies, either expressed or implied, of ATR In- 
ternational, the Systems Development Foundation, or 
the Canadian government. 
t Fellow of the Canadian Institute for Advanced 
Research. 
There is something special about performative 
sentences, sentences such as "I promise to return": 
uttering them makes them true. How and when 
is this possible? Not all verbs can be uttered in 
the first-person present tense and thereby make 
the sentence true. In general, the successful verbs 
seem to correspond to those naming illocution- 
ary acts, but not to perlocutionary ones such as 
"frighten." But, even some illocutionary verbs 
cannot be used performatively: e.g., "I lie to you 
that I didn't steal your watch" is self-defeating 
\[12\]. So, which verbs can be use performatively, 
and in Searle's words \[10\], "how do performatives 
work?" 
Any theory of illocutionary acts needs to pro- 
vide a solution to questions such as these. But, 
such questions are not merely of theoretical in- 
terest. Natural language database question- 
answering systems have been known to receive 
performative utterances \[14\], dialogue systems 
that recognize illocutionary acts (e.g., \[6\]) will 
need to infer the correct illocutionary force to 
function properly, dialogue translation systems \[5\] 
will have to cope with markers of illocutionary 
79 
force that function performatively (e.g., sentence 
final particles in Japanese), and proposals for 
"agent-oriented programming languages" \[7, 13\], 
as well as Winograd and Flores' \[15\] COORDINA- 
TOR system, are based on performative communi- 
cation. For all these systems, it is important to 
understand the semantics and pragmatics of such 
communicative acts, especially their intended ef- 
fects. To do so, one needs a full theory of il- 
locutionary acts, and a formal theory that pre- 
dicts how utterances can be made true by uttering 
them. 
The currently accepted theory of performatives 
is that they are in fact assertions, hence true or 
false, and additionally constitute the performance 
of the named illocutionary act, in the same way 
as an indirect reading of an illocutionary act is 
obtained from the direct illocutionary act. That 
is, the named illocutionary act is derived from the 
assertion as an indirect speech act. The most com- 
pelling defense of this performative-as-assertion 
analysis that we are aware is that of Bach and Har- 
nish \[1\], who address many of the linguistic phe- 
nomena discussed by Sadock \[9\], but who, we be- 
lieve, have misanalyzed indirect speech acts. How- 
ever, in a recent paper, Searle \[10\] forcefully crit- 
icizes the performative-as-assertion approach on 
the following grounds: 
• Assertions commit the speaker to the truth 
of what is asserted 
• Performative statements are self-referential 
• "An essential feature of any illocutionary act 
is the intention to perform that act" 
Searle claims that accounts based on self- 
referential assertions are "doomed to failure" be- 
cause one cannot show that being committed to 
having the intention to be performing the named 
illocutionary act entails that one in fact has that 
intention. Moreover, he questions that one should 
derive the named illocutionary act from an asser- 
tion, rather than vice-versa. However, Searle has 
imparted into Bach and Harnish's theory his no- 
tion of assertions as commitments to the truth 
without providing a precise analysis of commit- 
ment. What may be doomed to failure is any at- 
tempt to base an analysis of performatives on such 
a theory of assertions. 
This paper provides a formal analysis of per- 
formatives that treats them as declarative utter- 
ances, not initially as assertions, does not succumb 
to Searle's criticisms, and does not require an en- 
tirely new class of illocutionary acts (the "dec- 
larations") as Searle and Vanderveken \[12\] have 
proposed. The analysis is offered as another ade- 
quacy criterion for our theory of illocutionary acts. 
That theory, more fully explicated in \[3\], is based 
on an analysis of the individual rational balance 
agents maintain among their beliefs, goals, inten- 
tions, commitments, and actions \[2\]. 
As desiderata for the theory of performatives, 
we demonstrate that the analysis meets two prop- 
erties: 
• A sincere utterance of "I request you to open 
the door" is both a request and an assertion, 
yet neither illocutionary act characterization 
is derived from the other. 
• "I lie that the door is open" is self-defeating. 
Briefly, the ability to capture performatives is 
met almost entirely because such utterances are 
treated as indicative mood utterances, and be- 
cause illocutionary acts are defined as attempts. 
Since attempts depend on the speaker's beliefs and 
goals, and these mental states are introspectable 
in our theory if a speaker sincerely says, for ex- 
ample, "I request you to open the door," he must 
believe he did the act with the requisite beliefs and 
goals. Hence, the utterance is a request. 
To meet the desiderata we need first to present, 
albeit briefly, the theory of rational interaction, 
the treatment of declarative mood utterances, and 
then the illocutionary act definitions for request- 
ing and asserting. Finally, we combine the vari- 
ous analyses natural language processor's task by 
making explicit the intended word sense of the ac- 
tion, and by reducing the combinatorics inherent 
in determining the attachment of the prepositional 
phrases. 
80 
2 Abbreviated theory of rational 
action 
Below, we give an abbreviated description of the 
theory of rational action upon which we erect a 
theory of intention. The theory is cast in a modal 
logic of belief, goal, action, and time. Further de- 
tails of this logic can be found in \[2\]. 
2.1 Syntax 
The language we use has the usual connectives of a 
first-order language with equality, as well as opera- 
tors for the propositional attitudes and for talking 
about sequences of events: (BEL x p) and (GOAL x 
p) say that p follows from x's beliefs or goals (a.k.a 
choices) respectively; (AGT x e) says that x is the 
only agent for the sequence of events e; el _<as says 
that el is an initial subsequence of e2; and finally, 
(HAPPENS a) and (DONE a) say that a sequence 
of events describable by an action expression a will 
happen next or has just happened, respectively. 
Versions of HAPPENS and DONE specifying the 
agent (x) axe also defined. 
An action expression here is built from variables 
ranging over sequences of events using the con- 
structs of dynamic logic \[4\]: a;b is action composi- 
tion; a\[b is nondeterministic choice; a\[\[b is concur- 
rent occurrence of a and b; p? is a test action; and 
finally, a* is repetition. The usual programming 
constructs such as IF/THEN actions and WHILE 
loops, can easily be formed from these. Because 
test actions occur frequently in our analysis, yet 
create considerable confusion, read p?;a as "action 
a occurring when p holds," and for a;p?, read "ac- 
tion a occurs after which p holds." We use e as 
a variable ranging over sequences of events, and a 
and b for action expressions. 
We adopt the following abbreviations and do- 
main predicates. 
(BEFORE a p) de___f (DONE p?;a) z 
(AFTER a p) def= (HAPPENS a;p?) 
def <~p -- =le (HAPPENS e;p?). 
(LATER p) d~f = ~p A Op. 
1This differs from the BEFORE relation described 
in \[3\], which is here labelled PRIOR. 
def Op = -~<>-=p. 
(PRIOR p q) dej Vc (HAPPENS c;q?) D 
3a (a < c) A (HAPPENS a;p?). 
The proposition p will become true no later than 
q. 
def (KNOW x p) = p A (BEL x p). 
(IMPERATIVE s) means that sentence s is an im- 
perative. 
(DECLARATIVE s) means that sentence s, a string 
of words, is a declarative. 
(MAIN-VERB s v), (TENSE s tense), (COMPLE- 
MENT s s'), (D-OBJECT s np), (SUBJECT s np), 
are all syntactic predicates intended to have the 
obvious meanings. 2 
(TRUE s e) means that sentence s is true with re- 
spect to some event sequence • (which we will say 
has just been done.) 
(REFERS np x e) means that noun phrase np refers 
to thing x with respect to event e. 
(FULFILL-CONDS s • e') means that event • ful- 
fills the satisfaction conditions, relative to event 
e', that are imposed by sentence s. 3 For example, 
ifs is "wash the floor," e would be a floor-washing 
event. 
2.2 Assumptions 
The model we are developing embodies various as- 
sumptions constraining beliefs and choices (goals). 
First, BEL has a "weak $5" semantics, and GOAL 
has a "system K" semantics. 4 Among the remain- 
ing assumptions, the following will be used in this 
paper. 5 
Beliefs imply choice: 
(BEL x p) D (GOAL x p). 
2Feel free to substitute your favorite syntactic 
predicates. 
3TRUE REFERS, and FULFILL-CONDS are just 
placeholders for semantic theories of truth, reference, 
and the meanings of imperatives, respectively. Their 
last event arguments would be used only in the inter- 
pretation of indexica\]s. 
4See other work of ours \[2\] for a full model theory. 
5In other words, we only deal with semantic struc- 
tures where these propositions come out true. 
81 
This means that agents choose amongst worlds 
that are compatible with their beliefs. 
Goals are known: 
I:::(GOAL x p) - (BEL x (GOAL x p)). 
Memory: 
p (DONE x (BEL x p)?;e) = 
(BEE x (DONE x (BEE x p)?;e)). 
That is, agents remember what their beliefs were. 
3 Individual Commitments and In- 
tentions 
To capture one grade of commitment that an agent 
might have toward his goals, we define a persistent 
goal, P-GOAL, to be one that the agent will not 
give up until he thinks certain conditions are sat- 
isfied. Specifically, we have 
Definition 1 (P-GOAL x p q) def= 
(1) (BEt x -~p) ^ 
(2) (GOAL x (LATER p)) A 
(3) \[KNOW x 
(PRIOR \[(BEL x p)V(BEL x n-~p)v(eEL x "-,q)\] 
-~\[GOAL x (LATER p)\])\]. 
That is, the agent x believes p is currently false, 
chooses that it be true later, and knows that before 
abandoning that choice, he must either believe it 
is true, believe it never will be true, or believe q, 
an escape clause (used to model subgoals, reasons, 
etc.) is false. 
Intention is a species of persistent goal. We 
analyze two kinds of intentions, those to do ac- 
tions and those to achieve propositions. Accord- 
ingly, we define INTEND1 and INTEND2 to take 
action expressions and propositions as arguments, 
respectively. 
Definition 2 Intention: def 
(INTEND1 x a q) = 
(P-GOAL x \[DONE x (BEL x (HAPPENS a))?;a\] q). 
(INTEND~ x p q) def= 
(P-GOAL x 
3e\[HAPPENS x 
(BEE x 3e' (HAPPENS x e';p?))?;e;p?\] 
q) 
Intending to do an action a or achieve a proposi- 
tion p is a special kind of commitment (i.e., per- 
sistent goal) to having done the action a or having 
achieved p.¢ However, it is not a simple commit- 
ment to having done a or e;p? for that would al- 
low the agent to be committed to doing something 
accidentally or unknowingly. Instead, we require 
that the agent be committed to arriving at a state 
in which he believes he is about to do the intended 
action next. 
This completes a brief discussion of the founda- 
tional theory of intention and commitment. Next, 
we proceed to define the more specific concepts 
needed for analyzing communicative action. 
4 Utterance Events 
We begin the analysis of utterance events by 
adopting a Gricean correlation of an utterance's 
features (e.g., syntactic mood or sentence-final 
particles in Japanese) with the speaker's mental 
state, termed a "core attitude" in \[3, 8\]. Very 
roughly, a declarative utterance $ will be corre- 
lated with the speaker's believing the uttered sen- 
tence is true, and an imperative utterance will 
be correlated with the speaker's wanting the ad- 
dressee to do some action that fulfills the condi- 
tions imposed by the sentence. Let us notate these 
correlations as: 
DECLARATIVE =~ (aLL x (TRUE s e)) 
IMPERATIVE =~ (GOAL x 
03# (DONE y e') A 
(FULFILL-CONDS s e' e) 
We formalize this notation below. 
Someone who thinks he is observing an utter- 
ance event will come to believe the speaker is in 
the correlated mental state, unless he has other 
beliefs to the contrary. For example, if the ob- 
server thinks the speaker is lying, he believes that 
the speaker does not believe the uttered sentence 
is true. But, because he may think the speaker 
takes himself to be especially convincing, the ob- 
server may still believe that the speaker thinks the 
observer is deceived. Hence, he would believe the 
6For simplicity, we omit here one condition from 
the definition of INTEND2 in \[2\]. 
82 
speaker thinks that he thinks the speaker believes 
p. 
This type of reasoning can continue to further 
levels. In general, if an utterance is produced 
when there are no countervailing observer beliefs 
at a certain level of nesting, then the result will 
be, at the given level of nesting, that the speaker 
is taken to be in the correlated mental state \[8\]. 
To be able to state such conditions, we need to 
be able to refer easily to what a person x believes 
about what y believes about what x believes etc., 
to arbitrary depths. To do so, we use the notion 
of ABEL. 
Definition 3 (ABEL n x y p) de__f 
(BEL x (BEL y (BEL x ...(BEL x p )...) 
That is, ABEL characterizes the nth alternating 
belief between x and y that p, built up "from out- 
side in," i.e, starting with x's belief that p. On 
this basis, one can define unilateral mutual belief 
-- what one agent believes is mutually believed -- 
as follows. 
Definition 4 (BMB x y p) def= Vn(ABEL n x y p) 
In other words, (BMB x y p) is the infinite conjunc- 
tion (BEL x p) A (BEL x (BEL y p)) ^... Finally, 
we define mutual belief and mutual knowledge as 
follows. 
Definition 5 (MB x y p) dej (BMB x y p) A 
(BMB y x p). 
(MKxyp) de---fpA(MBxyp). 
Utterance events can produce effects at any (or 
no) level of alternating belief. For example, the 
speaker may not be trying to communicate any- 
thing to an intended observer. Illocutionary acts 
will be defined to require that the speaker intend 
to produce BM Bs. In what follows, it is important 
to keep in mind the distinction between utterance 
events and full-blooded communicative acts. 
4.1 Notation for Describing Utterance 
Events 
We now provide a formal notation for this corre- 
lation of utterance form and the speaker's mental 
state as a kind of default axiom (cf. \[8\]). First, we 
specify who is speaking (spkr), who is observing 
(obs, which includes the speaker and addressee, 
but also others), who is being addressed (addr), 
and what kind of sentence (s) has been spoken 
(indicated by q~). We shall assume that everyone 
knows that a given utterance is of a given syn- 
tactic type (e.g., declarative), that speakers and 
addressees are observers, and that observers are 
known by all to be observing. 7 
Definition 6 ~ =~ ~ de_/ 
V spkr, obs, addr, e, s, n 
(KNOW obs (DONE spkr e) A 
(UTTER spkr addr s e) A (q~ s)) ^ 
,-,(ABEL nobs spkr 
(BEFORE • 
,-,(GOAL spkr 
\[AFTER • 
(KNOW addr 
(BEFORE • o~))\]) )) 2) 
(ABEL nobs spkr 
(BEFORE • 
t~ A (GOAL spkr 
\[AFTER • 
(KNOW addr 
(BEFORE • a))\]) )) 
That is, • =~ ~ is an abbreviation for a quan- 
tified implication roughly to the effect that if an 
observer obs knows that • was just done, where 
• was an uttering to addressee addt of a sentence 
s in syntactic mood q~, and obt does not believe 
that • was done when the speaker did not want the 
addressee to come to know that the core speaker- 
attitude a associated with utterances of that type 
held, then obs believes that the speaker in fact 
wanted the addressee to know that o~, and so he, 
the observer, believes that c~ held just prior to 
the utterance. The notation states that at each 
level of alternating belief for which the antecedent 
holds, so does the consequent. The symbol '=~' 
can now be understood as a textual-replacement 
"macro" operator. 
Since these correlations are of the form 
VnP(n) 2~ Q(n)), they imply VnP(n) D VnQ(n). 
7The case of unseen observers is straightforward, 
but omitted here. 
83 
As we quantify over the positive integers indicat- 
ing levels of alternative belief, we can derive the 
conclusion that under certain circumstances, addr 
thinks it is mutually believed (in our notation, 
BMB'ed) that the speaker spkr wants addr to know 
was true. 
Notice that right after the utterance, we are 
concerned with what mental state the observer 
thinks the speaker chose to bring about in the ob- 
server with that utterance. That is, the condition 
on utterance events involves the speaker's wanting 
to get the observer to know something, Without 
this temporal dimension, our performative analy- 
sis would fail. The analysis of performatives will 
say that after having uttered such a sentence, or 
while uttering it, the speaker believes he has just 
done or is doing the named illocutionary act. Typ- 
ically, prior to uttering a performative, the speaker 
has not just performed that speech act, and so he 
would believe his having just done so is false. So, if 
the condition on utterance events in Domain :Ax- 
iom 1A involved only what the speaker believed 
or wanted to be true prior to the utterance, rather 
than after, all performatives would fail to achieve 
the observer's coming to believe anything. 
We can now state the correlation between ut- 
terance form and a speaker's mental state as a 
domain axiom. 
Domain Axiom 1 Declaratives and 
Imperatives: 
A. ~=DECLARATIVE =~ (BEL spkr (TRUE s e)) 
B. I= IMPERATIVE :=~ (GOAL x 
O3e'(DONE y e') ^ 
(FULFILL-CONDS s e' e) 
Below, we present our definitions of illocutionary 
acts. Further justification can be found in \[3\]. 
5 Illocutionary Acts as Attempts 
Searle \[11\] points out that an essential condition 
for requesting is that the speaker be attempting to 
get the addressee to perform the requested action. 
We take this observation one step further and de- 
fine all illocutionary acts as attempts, hence de- 
fined in terms of the speaker's mental states. At- 
tempts involve both types of goal states, GOAL 
(merely chosen) and INTEND (chosen with com- 
mitment), as noted below. 
de\] Definition 7 {ATTEMPT x e p q tl} = 
tI?;\[(BEL x -,~p A ,,-q) A 
(INTEND1 x tl?;e;p? (GOAL x Oq)) A 
(GOAL x Oq)\]?; • 
That is, an attempt to achieve q via p is a complex 
action expression in which x is the agent of event • 
at time tl, and prior to e the agent believes p and 
q are both false, chooses that q should eventually 
be true, and intends, relative to that choice, that • 
should produce p. So, q represents some ultimate 
goal that may or may not be achieved by the at- 
tempt, while p represents what it takes to make 
an honest effort. 
5.1 Definitions of Request and Assert 
To characterize a request or, for that matter, any 
illocutionary action, we must decide on the appro- 
priate formulas to substitute for p and q in the def- 
inition of an attempt. We constrain illocutionary 
acts to be those in which the speaker is committed 
to understanding, that is, to achieving a state of 
BMB that he is in a certain mental state. Below is 
a definition of a speaker's requesting an addressee 
to achieve p. 
Definition 8 {REQUEST spkr addr • p tl} def= 
{ATTEMPT spkr • 
\[BMB addr spkr 
(BEFORE • 
(GOAL spkr 
Op A 
\[AFTER • 
(INTEND~ addr p 
\[(GOAL spkr Op) A 
(HELPFUL addr spkr)\] )\])\]\] 
3e' (DONE adclr e';p?) 
tl} 
That is, event • is a request at time tl if it is 
an attempt at that time to get the addressee to 
84 
achieve some condition p while being committed 
to making public that the speaker wanted: first, 
that p eventually be achieved; and second, that 
the addressed party should intend to achieve it 
relative to the speaker's wanting it achieved and 
relative to the addressee's being helpfully disposed 
towards the speaker. 
The illocutionary act of asserting will be defined 
as an attempt to make the speaker's believing the 
propositional content mutually believed. 
def Definition 9 {ASSERT spkr addr • p tl} = 
{ATTEMPT spkr addr • 
\[BMB addr spkr 
(BEFORE e 
\[GOAL spkr 
(AFTER • 
\[KNOW addr 
(BEFORE • 
(BEL spkr p))\])\])\] 
(BMB acldr spkr (BEFORE e (BEL spkr p))) 
h} 
More precisely, assertions at time tl are defined 
as attempts in which to make an "honest effort," 
the speaker is committed to getting the addressee 
to believe that it is mutually believed that the 
speaker wanted prior to the utterance that the 
addressee would come to know that the speaker 
believed p held then. That is, just like a request, 
an assertion makes public that the speaker wants 
the addressee to know what mental state he was 
in. Although he is committed to that, what the 
speaker has chosen to achieve is not merely to 
make public his goal that the addressee know what 
mental state he was in, but to make public that 
he was in fact in that state of believing p. For 
an INFORM, the speaker would choose to achieve 
(KNOW addr p). 
6 Performatives 
To illustrate how performatives work, we show 
when both assertions and requests can be derived 
from the utterance of the performative "I request 
you to <do act>." The important point to notice 
here is that we have not had to add to our ma- 
chinery; performative utterances will be treated 
exactly as declarative utterances, with the excep- 
tion that the content of the utterance will make 
reference to an utterance event. 
6.1 Request Reports 
Let us characterize the truth conditions of the 
family of declarative sentences "x requests y to 
(imperative sentence sl). " Let s be such a sen- 
tence. Let ct be 3el(DONE y el) A (FULFILL- 
CONDS s' ez e). We ignore most syntactic con- 
siderations and indexicality for reasons of space. 
Domain Axiom 2 Present tense requests 
J= Vx, y, e, tl, (DONE h?;e) ^ 
(SUBJECT s ~) A (D-OBJECT s y) A 
(REFERS z x e) A (REFERS y y e) D 
(TRUE s e) - (DONE x {REQUEST x y e ~ tl}) 
That is, if event • is happening and the sentence s 
is a present tense declarative sentence whose main 
verb is "request," whose subject x refers to per- 
son x, and whose direct object Y refers to person 
y, then the sentence is true iff x is requesting the 
addressee y to fulfill the conditions of imperative 
sentence s'. A bare present (or present progres- 
sive) tense sentence is true when the event being 
described is contemporaneous with the event of 
uttering it. s This definition applies equally well 
to "John requests Mary to ..." as it does when I 
utter "I request you to ..." For the former, such 
sentences are likely to be narrations of ongoing 
events. 9 For the latter, the event that is happen- 
ing that makes the utterance true is the speaker's 
uttering of the sentence. 
By our definition of request, for x to request 
y to achieve p, x has to attempt to get y to do 
some action intentionally to fulfill the sentence s', 
by making that goal mutually believed between 
them. Thus, to say x requested y to do something 
is only to say that x had the right beliefs, goals, 
and intentions. 
SSearle \[10\] correctly points out that performatives 
can be uttered in the passive, and in the first-person 
plural. 
9We are ignoring the habitual reading of bare 
present tense sentences because we do not have a se- 
mantics for them. 
85 
6.2 Performatives Used as Requests 
Next, we treat performative sentences as declar- 
atives. This means that the effects of uttering 
them are described by Domain Axiom 1A. We 
sketch below a proof of a general theorem re- 
garding performative requests, with s being the 
declarative sentence"I request you to(imperative 
sentence Sl) , and c~ being 3el(DONE addr el) A 
(FULFILL-CONDS S 1 e I e). We take the uttering 
of a sentence to be a unitary utterance event. 
Theorem 1 A Performative Request 
I=V spkr, addr, e, n, tl, 
(MK spkr addr (DONE spkr tl?;e) A 
(UTTER spkr addr e s)) A 
(BEFORE h?;e 
(GOAL spkr 
\[AFTER tl?;e 
(KNOW addr 
\[BEFORE tl?;e 
(BEL spkr (TRUE s e))\])\])) Z) 
(DONE {REQUEST spkr addr e a tl}) 
That is, we need to show that if the sentence "I 
request you to <imperative sentence>" has just 
been uttered at time tl sincerely, i.e., when the 
speaker wanted the addressee to know that he be- 
lieved the sentence was true, then a direct request 
has taken place at tl. 
Proof sketch: Essentially, one invokes the do- 
main axiom for declaratives at the first level of 
ABEL, entailing that the speaker believes that he 
believes that he has just done a REQUEST. Then, 
one expands the definition of REQUEST into an 
ATTEMPT, and then into its parts. The defini- 
tion of ATTEMPT is based on BEL, GOAL and 
INTEND, the first two of which are obviously in- 
trospectable. That is, if one believes one has them 
one does, and vice-versa. Hence, by the memory 
assumption, the speaker actually had them prior 
to the utterance. More critically, intending to act 
at time tl is also introspectable at time tl because 
agents know what they are doing at the next in- 
stant and because there is no time to drop their 
commitment \[2\]. Thus, one can repackage these 
mental states up into an ATTEMPT and then a 
REQUEST. 
6.3 Performatives Used as Assertions 
We have shown that the speaker of a sincere per- 
formative utterance containing an illocutionary 
verb has performed the illocutionary act named by 
that verb. Under somewhat stronger conditions, 
we can also prove that the speaker has made an 
assertion. As before, let s be "I request you to 
<imperative sentence>." 
Theorem 2 Perforrnatives Used as Assertions 
I::V spkr, addr, e, n, tl, 
(MK spkr addr (DONE spkr tl?;e) A 
(UTTER spkr addr • s)) A 
\[BEFORE • 
(BEL spkr 
\[AFTER e 
Vn~,(ABEL n addr spkr 
(BEFORE e 
~(GOAL spkr 
\[AFTER • 
(KNOW addr 
\[BEFORE • 
(BEL spkr (TRUE s e))\]\] 
This default condition says that before the ut- 
terance, the speaker believed there would be no 
addressee belief after the utterance event (at any 
level n) to the effect that prior to that event the 
speaker did not want the addressee to come to 
know that the speaker believed (TRUE s e). Given 
Domain Axiom 1A, and the fact that BEL entails 
GOAL, this suffices to entail the definition of asser- 
tion. Notice that whereas requesting was derived 
in virtue of the content of the utterance, an asser- 
tion was derived by default assumptions regarding 
lack of belief in the speaker's insincerity. 
7 'Lie' is not a performative 
Some illocutionary verbs such as "lie, .... hint, .... in- 
sinuate," cannot be achieved performatively. The 
following analysis shows a general model for why 
such verbs naming covert acts cannot be perfor- 
matively achieved. 
A reasonable definition of lying is the following 
complex action: 
86 
Definition 10 {LIE spkr addr e p} de__f 
(BEL spkr ~p)?;{ASSERT spkr addr e p tl} 
That is, a lie is an assertion performed when the 
speaker believes the propositional content is false. 
For "I lie to you that the door is open" to be 
a successful performative utterance, it would have 
to be true that the utterance is a lie. We would 
have to show that the uttering of that declarative 
sentence results in a lie's having been done. More 
generally, we provide a putative statement of the 
truth conditions of "x lies to y that <declarative 
sentence s'> ." Call the main sentence s. 
Domain Axiom 3 Supposed Truth Conditions 
for Performative Lying 
l:: Ve, x, y, tl, (DONE h?:e) A (REFERS x x e) A 
(REFERS y y e) D 
(TRUE s e) - 
(DONE {LIE x y e (TRUE s' e) tl} ) 
That is, if s and s' are declarative sentences of 
the appropriate syntactic form, x refers to x and 
y refers to y, then s is true iff in performing it at 
time tl, x was lying that sentence s' is true. 
So we can prove the following. Let the sentence 
s be "I lie to you that <declarative sentence s'>." 
Theorem 3 Lies are not performative 
~V spkr, addr, e, n 
(MK spkr addr \[(DONE spkr tl?;e) A 
(UTTER spkr addr • s)\]) D 
,-,(DONE {LIE spkr addr e (TRUE s e) tl}) 
In other words, you cannot perform a lie by saying 
"I lie that ..." 
Proof Sketch: Assume that it is mutually be- 
lieved that the speaker has uttered declarative 
sentence s. Now, apply Domain Axiom 1A. By 
assumption, the first conjuct of the antecddent 
holds. There are then two cases to consider. First, 
assume (**) the second conjunct holds (say, at 
level n = 1), i.e., the addressee does not believe 
the speaker did not want him to know that he be- 
lieved s' was true. In virtue of the supposed truth 
conditions on lying, spkr would have to have been 
lying. By expanding its definition, and using the 
memory and introspectability properties of BEI_, 
GOAl', and INTEND the addressee can conclude 
that, before the utterance, the speaker wanted him 
not to know that the speaker believes that in ut- 
tering S, he was lying. But, this contradicts the 
assumption (**). Since the speaker in fact uttered 
the sentence, that assumption is false, and the ad- 
dressee believes the speaker did not in fact want 
him to know that he believed the sentence was 
true. This renders impossible the intentions to be 
achieved in asserting, which are constitutive of ly- 
ing as well. 
Now, assume (**) is false, so the addressee in 
fact believes the speaker did not want him to know 
that s' was true. Again, this immediately makes 
the speaker's intentions in asserting, and hence ly- 
ing, impossible to achieve. So, in neither case is 
the utterance a lie. If the addressee believes the 
speaker is a competent speaker of the language, 
the speaker must have intended some other inter- 
pretation. 
8 Conclusion 
Requesting works well as a performative verb be- 
cause requesting requires only that the agent has 
made an attempt, and need not have succeeded in 
getting the hearer to do the requested action, or 
even to form the right beliefs. Some verbs can- 
not be used performatively, such as "frighten," 
because they require something beyond a mere 
attempt. Hence, such verbs would name action 
expressions that required a particular proposition 
p be true after the utterance event. When the ut- 
terance event does not guarantee such a p, the use 
of the performative verb will not be possible. 
On the other hand, certain utterances (perfor- 
mative or not), when performed by the right peo- 
ple in the right circumstances, make certain insti- 
tutional facts hold. So, when a clergyman, judge, 
or ship captain says "I now pronounce you hus- 
band and wife," the man and woman in question 
are married. In our framework, there would be a 
domain axiom whose antecedent characterizes the 
circumstances, participants, and nature of the ut- 
terance event, and whose consequent asserts that 
an institutional fact is true. The axiom is justified 
not by the nature of rational action, but by the ex- 
istence of an institution. Such utterances could be 
87 
made with a performative prefix provided such at- 
tempts are made into successes by the institution. 
This paper has shown that treating performa- 
tive utterances as declarative sentences is a vi- 
able analysis, in spite of Searle's criticisms. The 
performative use of an illocutionary verb is self- 
guaranteeing when the named illocutionary act 
consists in the speaker's making an attempt to 
make public his mental state. In such cases, if 
the speaker thinks he has done so, then he has. 
However, we do not derive the named illocution- 
ary act from the assertion, nor vice-versa. Instead, 
both derivations may be made from the utterance 
event, but the assertive one is in fact harder to 
obtain as it has extra conditions that need to be 
satisfied. 
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