December, 1951
CREATIVE THINKING
by
J. R. Pierce
I have been asked to talk to you about creative thinking. While I am
glad to do this, I feel some trepidation about discussing a non-technical
subject, and I think I should tell you why.
It seems to me that engineering and science are sharply set apart from
all other fields of human activity. If I tell you that a certain theory
predicts the behavior of electrons or neutrons, or that a network designed
in such and such a way will have such and such properties, you can check
my statements by observing the particles or by testing the network. In
contrast, even a historian or a witness to an event can offer you only his
documents or his word to testify that what he recounts actually happened.
You can't check by making an experiment. When one deals, as I shall, with
surmises about partially-known experiences and events, you will be still
farther from being able to verify what I say. If I put forth an idea as
being plausible, you should be forewarned that people in other times and
other places have found witchcraft and astrology to be plausible, and a
host of other things which we regard as ridiculous. If I pose as an expert
in creative thinking or as an authority on creative thinking, I should at
least warn you that I have heard people whose individual actions and
decisions I respect greatly give forth generalizations and analyses for
which I had much less respect.
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Although I talk with some trepidation, I have no real pangs of
conscience. I will be honest and thoughtful to the best of my ability, and
I have warned you. Thus, despite my doubts, I shall thoroughly enjoy
talking about creative thinking. People like to discuss ill-understood
problems which seem more "human" and more "profound"
than the technical details of engineering and science. I hope that some
day someone will be able to talk about creative thinking in a sounder way
than I am able to, but he will probably get less pleasure from his science
than I shall from my fancy.
The other part of my trepidation has another cause. Suppose that what I
say is true and wise and constitutes good advice. What is the use of
saying it? Through a good while at the Bell Laboratories I have seen
certain people, figuratively, of course, hitting themselves on the heads
with hammers, sawing off their noses, trying to walk through brick walls,
riding off rapidly in all directions at once, lying under the flapdoodle
trees waiting for the fruit to fall in their mouths, and generally
behaving in what seem to me uninstructed if not irrational manners.
Surely, someone must have told them better. Sometimes I've tried to
myself. Yet year after year they pursue the same courses. What good does
it do to tell people non-technical things, anyway?. You may be able to
persuade a man to add 2 and 2 and get 4 rather than 5, but can his conduct
in more general matters be influenced? I don't know, and if it can't,
maybe that is a good thing. In any event, I
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don't intend to let this doubt as to the utility of what I say dull my
pleasure in saying it.
With these warnings and explanations, I propose to tell you how I feel
about creative thinking. Don't believe me if you don't want to. Don't
expect to get much good out of what I say. I hope it gives you some
pleasure.
I think the words of the subject deserve a little attention, although I
don't intend to give them a precise meaning. I think of creative thinking
as referring to the fact that something has been created through thought.
In our case, it may be a physical theory; the understanding of a class of
phenomena; it may be an invention; it may be a way of getting around a
difficulty; it may be an overall or a detailed design for a communication
system. What I want to do is to distinguish creative from original
and especially from bizarre
or novel. To me, creative thinking produces something substantial
and reasonably permanent, something which may be understanding, art, or a
piece of equipment.
Now, not all substantial accomplishments are the results of thinking. A
dictator may have a whole class of people liquidated; an executive may
order that no one with more than ten years' service shall achieve district
status. The results produced in such cases can be substantial and
reasonably permanent, but thinking is not necessarily involved.
In considering creative thinking, I associate thinking with that
ordered progress which we see so clearly in engineering
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and science and which we may find lacking in many other fields of human
endeavor.
In navigation, the quadrant marks a clear advance over the astrolabe,
and the sextent marks an even greater advance over the quadrant. A vacuum
tube of today is just plain better than a vacuum tube of 1920, and the
same thing is true of today's refrigerator. Today, through wave mechanics,
we understand things about the motions of electrons and about the
constitution of atoms which were completely hidden from us thirty years
ago.
In engineering and science, progress is evident in a series of steps,
each of which adds to what we already know or to what we already have done
or can do. It is a great part of the satisfaction of one who works in
these fields to contribute to this progress. It is of this progress, this
adding to our technical capabilities and knowledge, that I associate the
words creative thinking,
When I think back over fifteen years at the Bell Laboratories and
consider the examples of creative thinking which I have seen, one thing
which strikes me most forcibly is the variety of people who have added to
our technical capabilities and knowledge, and the variety of ways in which
they have done this creative thinking. People are widely different and
sometimes exasperatingly different. Moreover, the difference is not so
much that some people can do one job and others can't; it is that some
people will do a job in one manner and others in
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another. When we add the fact that there are many ways to achieve a
particular piece of creative thinking to the fact that there are many
sorts of creative thinking to be done, generalization becomes very
difficult and it is perhaps best to turn to particular examples.
As one rather extreme case, I know a man at the Bell Laboratories who
has a record of turning up one good thing after another. One can describe
his field roughly by saying that he works on small component parts. He
works in a diversely equipped laboratory and shop, with the aid of a
technical assistant, and there he not only invents devices and processes,
but he makes samples and even whole lots for other people to work with.
I find this man a very puzzling phenomenon. He works with devices and
processes which to me seem bewilderingly complex. Of all the multitude of
things which he might try, he has some way of hitting on the right things,
time after time. He must have some guiding principle of creative thinking
which helps him. I find this particularly striking because I have talked
with him about his work repeatedly, and I have never got the slightest
clue to his way of thinking.
I suppose that the uninitiated might say that anyone messing around in
a laboratory will come up with something new and useful. Experience shows
that this just isn't so. For experimental work to be fruitful, there must
be choice as to what is tried and the results of experiments must be
evaluated.
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It is clear that the man of whom I am speaking is doing creative
thinking of a high order. The fact that I cannot fully understand the
nature of his creative thinking shows a lack in me, not in him.
Does this man represent an important aspect of creative thinking? I
know several men around the Bell Laboratories who are much like this. But
even more important, I think that the thing on which the man I have
described relies so strongly helps many of us in some lesser degree. I
think I could even cite a homely example of this.
Once upon a time a man started to build an elaborate oscilloscope. When
it was almost complete and was working in a halting fashion, he left the
Bell Laboratories and went to work for Hughes, where he lived happily ever
after. The oscilloscope was turned over to a T.A. for debugging. Instead
of improving, the device suffered a series of relapses until it wouldn't
function at all. At this point it was turned over to another T.A., who is
now a T.S.A, by the way. The oscilloscope took a miraculous upturn and was
working well in a week or so. In my estimation, this showed at least some
creative thinking on the part of the TA.
We can describe the sort of thinking I have been discussing by a name
if we wish: intuition; skill; art. I am even willing to speculate on its
ingredients. Partly, I think it grows through long familiarity. A boy who
plays with erectors and graduates through hot rods will acquire a feel
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for things mechanical. He learns by some informal and partly
unconscious process. For such learning, I think that both interest and
long acquaintance are necessary. I believe that something else is
necessary as well; innate ability.
This type of intuitive thinking is extremely valuable. How are we to
get enough of it? I can't give any directions for teaching it or
practicing it; I think that we can only recognize it where it occurs and
value it highly. We must to some extent take it as it is. In the fairy
story, the man killed the goose that laid the golden egg in a foolish
investigation of the source. Intuitive thinkers must be treated tenderly
if they are to continue to function. One might even extend the parallel,
and invent a man who despised the goose because it couldn't tell how it
made the golden egg. In this connection, I can only drag up two old saws;
"gold is where you find it"; and, with some possible confusion
of thought, "don't look a gift horse in the mouth."
Because I have praised and valued intuitive thinking, even in extreme
forms, you may wonder whether I am advising you to practice it. The answer
is, not unless you can. I do say, by no means despise it. A device can be
good, an invention can be valuable even when its author cannot explain it
to another's satisfaction, But for heaven's sake, don't try this approach
unless you know by experience that you are good at it.
Let us turn to another sort of creative thinking. I know one man who
sits in an office and makes marks on pieces
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of paper. He thinks about other people's experiments. He makes up
mathematical theories which purport to tell, in terms of known physical
laws, what ought to happen when experiments are performed. He analyzes
experimental results and tries to find out what caused them. He can
explain to any competent man in detail just what he has done and why he
did it, although one may still wonder what inspired him to do it.
Is this man's thinking a mere gloss on someone else's work; is it only
an explanation of what we already know? No, it is not. Sometimes this man
finds that other's ideas about things are just wrong-headed and
misleading. In such cases he clears up their confusion and reorients their
thinking and their work. In other cases he foresees consequences which
others have not thought of. When he formulates problems in mathematical
form they become simpler and less puzzling, and he can foresee necessary
consequences which would escape one who thought in looser terms. Such a
man can make discoveries and inventions; these are not reserved for the
intuitive experimenter.
Such theoretical workers provide the backbone, the skeletal structure
of engineering and science, without which these fields would collapse into
an amorphous mass of unrelated devices and facts. Without them we would
not have that clear and steady progress in art and understanding which
distinguishes engineering and science from other fields of human endeavor,
Do I advise all of you to become theorists? There is something to be
said for this in a small way at least, for we
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know what the tools are. As opposed to an intuitive appreciation of
things, physics and mathematics can be taught by fairly straightforward
methods. But, this is not necessarily true of the ability to use them. I
have known people with a good knowledge of physical laws, with an
extensive knowledge of mathematics and with considerable skill in its
manipulation who simply didn't know what to do with their knowledge. Such
people either can't get started on a problem, or else they get hopelessly
bogged down in details. Certainly, you shouldn't learn more mathematics
and theory than you can digest, make your own, and use effectively.
I have described two extreme sorts of people whom I have met; very
intuitive men who accomplish experimental results no one knows how, and
theorists who proceed by consistent and well ordered reasoning. Of course,
most of us have some of each of these qualities. I am thinking at the
moment of two people who as nearly as I can see get their good ideas while
carrying out experiments; they are prompted to creative thinking chiefly
through the behavior of the apparatus they work with. Yet, each of these
men is quite capable of expressing what he has done in clear-cut, even
mathematical, terms. I think also of a mathematician who with his own
hands builds machines and gadgets embodying his ideas.
I believe that this mixture of experimental insight and theoretical
understanding is perhaps the most successful equipment for creative
thinking. The
virtue of experiment is
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that, however complex the situation, nature always knows the right
answer, by definition, of course. Anyone who works in a laboratory
continually encounters unexpected phenomena, and some of these the
creative thinker can recognize, foster and turn to use.
On the other hand, theoretical or analytical ability can in itself be
both a guide to understanding new phenomena and a means for deducing
something useful from something which might otherwise be merely new and
puzzling.
What I have said so far has been about types of people and their
methods of tackling problems. The problems themselves are worthy of
consideration. Under what circumstances do people exercise their power of
creative thought? How do new ideas and things arise? Here I would like to
cite a particular, minor, personal example, and I will follow it with
others.
Over ten years ago I was working on a type of tube using an electron
beam. No one had a method of design which took space-charge into account
and produced a gun of predictable properties. I worried about the matter
for some time and finally I thought of a means of design. I spent quite a
while working this out theoretically and convincing myself and others that
it was sound. Then I wrote a paper describing it and published it in the
Journal of Applied Physics. Certainly, something was created here, for I
have found that practically everyone who works with dense electron beams
makes use of my work.
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In this case the thing which was created was really a published article
which helped other people to design electron guns. The tube I was working
on never came to anything. The bare idea of the gun wasn't the end
product, for I later found that a friend of mine had speculated about the
same idea, but he hadn't worked it out or written about it.
One moral I would like to draw from this illustration is that any
challenging job can be a spur to creative thinking. I didn't set out to do
something new or something clever; I was forced to think by being faced
with a problem which I took seriously and wanted to solve.
Of course, to serve as a stimulus a job must be a real and an
interesting challenge to the man who works on it. Some men seem to find no
challenge in fields they haven't read about in the newspapers or heard
commended in college. I think that this is unfortunate and worth thinking
about.
Surprisingly interesting things can come out of jobs which may seem
very prosaic. Claude Shannon's application of Boolean algebra to switching
problems may seem to some more interesting than the original problems.
Shannon's work on communication theory might provide another example. From
what I know, this was inspired by some discussions of novel ways of
modulation such as mixtures of amplitude and phase modulation, and finally
pulse-code modulation, Today, communication theory is a broad field
related to physics, psychology and I don't know
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what all. I myself have been led to far and interesting fields in
connection with traveling-wave tubes, yet as far as I am concerned, as
much as anything this arose through repeated insistence on the part of
Ralph Bown that resonant circuits limit the bandwidth of vacuum tube
amplifiers and that someone should do something about it.
I have said that work on a challenging job can inspire creative
thinking, but you will note that an initial inspiration is not enough; one
must do something about his insights and ideas in order to create
anything. In the case of the new means for designing an electron gun, I at
least worked out some of the ideas and published a paper, while a friend
who had the same general ideas but less interest in the matter did
nothing. Ideas which are not developed and carried to some conclusion
become as if they never had been. The process of creative thinking can
easily be interrupted before anything is really created, and in such cases
whatever time and effort have been expended are totally lost.
Some simple, isolated ideas can be worked out and given physical form
or published by one man in a short time. In other cases the process of
creation is long and necessarily involves many people. I think
particularly about some aspects of the L3 carrier development, and about
the work that led to the 416A microwave triode.
An example drawn from the L3 development is the application of quality
control and statistical methods to every
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vital component used in the system and to the system as a whole. For
one thing, this meant that everyone working directly on the project had to
keep continually in mind the meaning and details of this approach. For
another thing, those who worked directly on the project had to cooperate
closely with groups which produced components such as, for example, vacuum
tubes. For the first time, specifications were put on all tube parameters
affecting system performance, and for the first time tolerances were set
on the basis of control limits of a process which was known to be in
control.
I am in no position to go into further details here, but the point is
that this seemingly simple idea of applying quality control in system
design could be called into real existence only through persistent work
over a period of years by a whole group of people.
Another example is provided by the development of the 416A triode. The
original and startling germ of a creative idea was that after all these
years a triode might still be the best amplifier for microwaves, if only
the spacing were close enough and the grid fine enough. An auxiliary idea
was that close enough spacings could be attained and held by grinding the
cathode and a surrounding ceramic co-planar, and then supporting the grid
from the ceramic. These were, however, mere germs of an idea. Something
real and complete was brought into existence only after years of
concentrated effort, including the inauguration of a program of cathode
studies which is still being pursued for other purposes.
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My position so far has been that one needs some ability, intuitive or
theoretical, and preferably both, for creative thinking. Frequently, one
needs the inspiration of working hard on a job. One further needs the
persistence to bring an idea into real being. There is, of course, more
than this: one needs the right environment; the right job.
I believe that there are certain general specifications which an
environment should meet to foster creative thinking. For one thing, a man
should get credit, encouragement and reward if he does produce good, new
things. He should feel that his supervisor is helping him and advertising
his success, not competing with him or exploiting him. If the man is in a
position to exploit his idea himself, he should be allowed to; if it must
be turned over to someone else, the originator should get his fair share
of credit. In any event, he should be encouraged to publish what he has
done, for his own good and for the good of the Bell Laboratories.
For another thing, a man should not be plagued with any irrelevant
matters which he can be spared. It is hard enough for him to keep the
technical part of a job in hand and to take care of his personal relations
with other technical men. To encounter red tape or inefficiency or
inadequacy in purchasing, in shops, in space allocations and changes, in
personnel matters, and, especially, in interdepartmental relations cannot
help but have a bad effect.
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What about actual physical working arrangements? Some of the best work
of which I know has been done in gloomy, dirty, noisy and even crowded
university laboratories. This of course shows a certain triumph of the
intellectual or spiritual over the physical, and indeed I believe that the
matters I have mentioned a little earlier are much more important than are
physical surroundings.
It seems to me reasonable that one should have good physical
surroundings if his employers can afford them. Some people may be
sensitive to noise, and why should a laboratory or an office be noisy?
Some people may be sensitive to heat, and air conditioning is nice if one
can afford it. Personally, except for some cases in which certain
standards are set by technical requirements of special jobs, I regard the
nature of surroundings as something to be chosen more with regard to
custom, decency, and respect for people as human beings, than with regard
to their influence on quality or quantity of work. If I were to make a
personal choice as to surroundings, I would like most of all authority to
change and arrange them to suit convenience, without regard to general
plans or rules. I think that this is something which can easily be
overlooked by people who no longer do laboratory work.
These general matters of satisfactory supervision, satisfactory
facilities and, perhaps, suitable physical surroundings, I believe to be
very important. I think that for most people the specific nature of the
job they are asked to do is of
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less importance. A person with some intuitive grasp of engineering and
an understanding of some basic physical laws and mathematics can tackle
almost any engineering problem and do creative work, granted the right
general atmosphere. There are, of course, exceptions. I believe that
highly exceptional people who have to be carefully fitted to a particular
field or job are in the minority. I have no trouble thinking of examples,
however; people who succeeded after changing jobs where they had failed
before, and people whom I cannot imagine doing anything very much
different from what they are doing now.
For instance, an extremely intuitive person who thinks with his hands
in a laboratory is not the man to do long-range systems planning. He
belongs in a niche by himself, in research or advanced development. A man
with a really profound knowledge of mathematics and broad interests
shouldn't be tied down to a single long-range project, where he will soon
have contributed everything his particular talents have to offer. And, a
small minority of workers seem to be real self-starters, who break into
intellectual combustion spontaneously without the spur of a job and think
truly profound thoughts. In their exceptional case, a set task is bad,
rather than good, and they should not be burdened with demands or
instructions.
On the other hand, for each of such exceptional people I have certainly
seen at least one rather unsuccessful man who didn't like and didn't work
very hard at a job of which he could have made something, but who longed
for some other work, and in
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many cases for work which he could not do well. Occasionally such men
do produce a stream of ideas outside of their field, but most often the
ideas are not very good, because they don't strike at the heart of the
problem, and the ideas are seldom worked out far enough to be anything but
material for conversation.
Now I have talked about types of ability, about a job as an
inspiration, about carrying ideas from a glimmering into real being, and
about working conditions and jobs. You may believe that I have omitted the
really vital point; granted some sort of ability, some sort of problem and
reasonably satisfactory surroundings, how does one get the sort of idea
that can really advance the art and put us on territory where we weren't
before?
One source of ideas which no one should overlook is the ideas of
others. The world is full of half-born ideas; ideas that came too soon;
ideas that were not fully appreciated by the men who had them; ideas that
someone is trying to promote. I have got some of my very best ideas from
other people, usually through personal contact or current publication.
There must be many ideas in the technical literature of past years, but in
my personal experience these have most often been turned up by the patent
department to show that I hadn't invented something when I thought I had.
As an example of an idea which I got from another, I will cite the
traveling-wave tube. In this case, I saw in a device which was on the
point of being abandoned as a solution for one problem potentialities
which other people seem to have been blind to.
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Sometimes, however, one can't find what he wants by shopping around.
How, then, does one get an idea when he is forced to have it himself? And
how does he bring it from a germ of an idea into true being?
Happily, there is much more agreement on this than one might imagine.
One gets new ideas by inspiration or accident, and one tests, verifies and
makes something of them by expert knowledge and hard work.
Let me tell the story of a couple of my ideas. I don't claim that they
are very good ideas, but they are about as original as any I have ever
had.
One evening W. B. Hebenstreit and I were working late at the
Laboratories, on a book which, incidentally, never got written. We had
been trying to deduce mathematically the effect on tube noise of the fact
that an electron beam is made up of electrons with many velocities.
Because many velocities were too much for our feeble mathematics, we
considered a beam composed of electrons of two velocities only. We quickly
deduced growing waves. The double-stream amplifier had been conceived. It
came into being through further straightforward mathematical work and
through experimental work by A. V. Hollenberg. Finally, alas, it was
dropped because its alleged advantages came to appear illusory.
For a number of years I have been interested in communication theory.
Because of this interest, I have repeatedly
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tried to concoct new and advantageous ways for encoding messages for
transmission. Some two years ago I had been thinking a lot about systems
with a random element, which have certain alleged general advantages. One
day I was talking casually with Claude Shannon, and he described to me in
a few words the system a worker outside of the Bell Laboratories had
devised. I didn't pay much attention while he was talking, but something
of what he had said stayed with me. Then, later in the day, I saw certain
advantages of this new system. The next day I went to see Claude and told
him that this was a fine idea. As I explained the advantages, he agreed,
but he observed that the system I was describing wasn't the one he had
told me about at all. I had invented a new system by listening carelessly
and pursuing my own thoughts. Since then I have done a good deal of
analytical work and further "inventing" in this connection and
A.L.Hopper has made an experimental system. I still have hopes for this
one.
While I had each of these ideas by accident, I had them only because I
had been thinking for a long time in the general field and racking my
brains for ways of doing things. Then, suddenly, there was an idea.
Sometimes the idea or the glimmering of an idea comes in a less accidental
manner, suddenly on the street as one did to the mathematician Henri
Poincare, or at night in bed. But it doesn't come without adequate
preparation. And, without adequate skill and considerable effort, nothing
will come of the
incomplete idea; inspiration and accident form only the starting point of
creation, not its accomplishment.
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It is because of belief in this sort of genesis of inspiration that I
feel that interest in and hard work on a job are more important than just
what job it is. If your job poses problems, if you take them seriously, if
your boss inspires and encourages you, then, granted even reasonable
ability, inspiration will come, and if you follow the inspiration up with
sound analysis and work you will have created something.
Now I will admit that there is one catch to this. Sometimes people have
good ideas, or the germs of good ideas, outside of the field of their
immediate work, There are several things which one can do in such a case.
One course is to write the idea down in your notebook, perhaps to get
it patented if you can, but to do nothing further. Some day, someone who
really needs the idea in his work will have the idea independently and
will really work it out. At this point you can flaunt your notebook and
perhaps your patent in his face, his boss's face, your boss's face, and so
on. Such behavior may give a lot of satisfaction to some people, but I
don't see just what it accomplishes,
Another course is to seek out someone to whom you think the idea might
be of use and to try to sell the idea to him, or rather, to give it to
him. The important thing is to persuade him to take it. As a secondary
consideration, you may write a memorandum, or a joint memorandum, or take
out a patent if he insists.
Sometimes you can't sell an idea. If the idea still seems good to you,
it is appropriate to state it clearly and as
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completely as you can in a memorandum and send it to all the people you
think might make use of it. Or, you can go further and publish it.
Sometimes an idea will seem so good and attractive that you want to
work on it yourself. If it's that good, your boss is likely to be
impressed with it himself, and so will other people, and you will get a
chance to work on it if you wish.
It seems to me that I have covered a lot of ground, and that I ought to
give some sort of brief summary and drawing together of what I have said.
I will make this very brief.
To me, creative thinking implies two things. First, something
reasonably substantial and enduring must be created, whether this be
embodied in a publication or a piece of apparatus. Second, something must
be added to the body of engineering or science, something which can be
clearly recognized as a step forward.
Creative thinking can proceed either from a logical approach to a
problem, or through an intuitive grasp of it. In exceptional people the
logical or the intuitive elements predominate very strongly. If you are
one of these, you may succeed only in a rather special sort of job. With a
moderate amount of both of these qualities you can do creative thinking in
connection with almost any job, provided that you find the job challenging
and that you aren't unduly distracted by non-technical or irrelevant
matters,
Things which make a job challenging are good general working conditions
and a good boss who inspires you, and who sees that you get recognition
and rewards.
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There is a large element of inspiration and accident in the genesis of
creative ideas, but the inspiration doesn't come and the accidents don't
happen to people unless they are prepared through hard work and hard
thought.
Creative thinking doesn't end with the initial idea. Unless one checks
and analyzes the idea and reduces it to an appropriate substantial form,
which may be a publication or a physical device, nothing has been
accomplished. Knowledge is what people know, not what they have surmised
or forgotten. The ratio of inspiration and perspiration varies from
creative idea to creative idea, but the perspiration is always there.
Finally, I might add that few satisfactions are so great for the effort
spent, or so enduring, as that of having taken a real step ahead in
engineering or science. In these pursuits progress is real, and it is
recognized and appreciated by all the fraternity of workers. I believe
that in no other field of human endeavor can the average worker achieve as
secure and enduring a place through his creative accomplishments. Next to
good pay, this should be a considerable inspiration and satisfaction to
us.
Historical Notes
This talk was discovered by my father, Herbert Anton Schneider, in his
papers. He was at Bell Laboratories, Murray Hill, NJ when he heard it. He
wrote '1952' on the top, so presumably he obtained the text January of
that year. He sent me a copy.
John Pierce
granted me permission
to put the talk on the web with no restraints or copyright reservations.
The pages were scanned by a Microtek ScanMaker 4 on a Power Macintosh
7600/120 with OmniPage Pro 8.0 and then edited into html.
To retain the flavor of the original text, which was typewritten, I
have kept it broken by the original pagination. I have made corrections
indicated in the text. There were a handful of other changes. To avoid
disrupting the flow but to keep a record since this is a historical
document, I have put them into invisible HTML comments.
I thank Denise Rubens for careful proofreading.
Thomas D. Schneider
National Cancer Institute
Laboratory of Experimental and Computational Biology
Frederick, Maryland 21702-1201
- Letter from Pierce giving permission to put this document on the
web:
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