ere being read, this machine would detect it, supposing that the
machine were in operating condition and all of the other qualifications
had been met. You see, Mr. Burris, no matter how poor a telepath a man
may be, he has some slight ability--even if only very slight--to detect
the fact that his mind is being read."

"You mean, if somebody were reading my mind, I'd know it?" Burris said.
His face showed, Malone realized, that he plainly disbelieved this
statement.

"You would know it," Dr. O'Connor said, "but you would never know you
knew it. To elucidate: in a normal person--like you, for instance, or
even like myself--the state of having one's mind read merely results in
a vague, almost subconscious feeling of irritation, something that could
easily be attributed to minor worries, or fluctuations in one's hormonal
balance. The hormonal balance, Mr. Burris, is--"

"Thank you," Burris said with a trace of irritation. "I know what
hormones are."

"Ah. Good," Dr. O'Connor said equably. "In any case, to continue: this
machine interprets those specific feelings as indications that the mind
is being ... ah ... 'eavesdropped' upon."

You could almost see the quotation marks around what Dr. O'Connor
considered slang dropping into place, Malone thought.

* * * * *

"I see," Burris said with a disappointed air. "But what do you mean, it
won't detect a telepath? Have you ever actually worked with a telepath?"

"Certainly we have," Dr. O'Connor said. "If we hadn't, how would we be
able to tell that the machine was, in fact, indicating the presence of
telepathy? The theoretical state of the art is not, at present,
sufficiently developed to enable us to--"

"I see," Burris said hurriedly. "Only wait a minute."

"Yes?"

"You mean you've actually got a real mind reader? You've found one? One
that works?"

Dr. O'Connor shook his head sadly. "I'm afraid I should have said, Mr.
Burris, that we did once have one," he admitted. "He was, unfortunately,
an imbecile, with a mental age between five and six, as nearly as we
were able to judge."

"An imbecile?" Burris said. "But how were you able to--"

"He could repeat a person's thoughts word for word," Dr. O'Connor said.
"Of course, he was utterly incapable of understanding the meaning behind
them. That didn't matter; he simply repeated whatever you were
thinking. Rather disconcerting."

"I'm sure," Burris said. "But he was really an imbecile