Nor do I recall any statement by Keynes - and I doubt that any
exists - to
challenge the view on the relationship between the axioms of science
and
empirical reality or "experience" which Einstein summarized as follows:
"The supreme task of the physicist is to arrive at those universal
elementary
laws from which the cosmos can be built up by pure deduction. There
is no
logical path to these laws; only intuition, resting on sympathetic
understanding of experience, can reach them." ('Principles of
Research', 1918
- reprinted in Albert Einstein - Ideas and Opinions, Dell Publishing
Company,
Laurel Printing, 1976, p. 221)
I must be misunderstanding you.
This passage from Einstein sets out a conception of physics that
Marshall
and Keynes, in the many passages I've quoted (including the one above),
explicitly reject as a conception appropriate for a "moral science" like
economics.
It assumes there are "universal elementary laws from which the cosmos
can be
built up by pure deduction." Marshall and Keynes explicitly reject this
assumption as a basis for economics on the ground that, unlike physics,
the
material of economics is not constant and homogeneous. Here are some
more
examples from the material I've previously quoted:
"if the subject-matter of a science passes through different stages of
development, the laws which apply to one stage will seldom apply without
modification to others; the laws of the science must have a development
corresponding to that of the things of which they treat." (Marshall,
Principles, Vol. 1, p. 760)
"though economic analysis and general reasoning are of wide
application, yet
every age and every country has its own problems; and every change in
social
conditions is likely to require a new development of economic
doctrines."
(Vol. 1, p. 37)
(This, by the way, is the aspect of Marshall picked out for emphasis by
Schumpeter to indicate (overoptimistically so far as economics itself is
concerned) why "his [Marshall's] teachings can never die", an aspect of
Marshall that Schumpeter explicitly contrasts with that aspect of Mill
with
which you seem to be claiming both Marshall and Keynes should be
identified.
"Its [Marshall's Principles] will last for an indefinite time not only
because teaching of such breadth and force merges into the inheritance
of
subsequent generations, but also because there is about it a peculiar
quality which effectively resists decay. Reared in an atmosphere that
was
full of slogans of evolutionary progress, Marshall was one of the first
economists to realize that economics is an evolutionary science
(although
his critics not only overlooked this element of his thought but in some
instances actually indicted his economics on the ground that it
neglected
the evolutionary aspect), and in particular that human nature he
professed
to deal with is malleable and changing in function of changing
environments.
But again, this is not what matters to us just now. What does matter is
that he carried his 'evolution-mindedness' into his theoretical work.
There
was no air of finality about it. Unlike Mill, he would never have said
that
some problem or other was settled for all time to come and that there
was
nothing about it that called for further explanation either by himself
or
any other writer. On the contrary, he was fully aware that he was
building
an essentially temporary structure. He always pointed beyond himself
and
towards lands into which it was not given to himself to enter. New
problems, ideas, and methods that are enemies to the work of other men,
thus
came to his own as allies. Within the vast fortified camp that the
built,
there was room - in fact, there was accommodation prepared in advance -
for
them all." (Schumpeter, 'Alfred Marshall's Principles: A Semi-Centennial
Appraisal', American Economic Review 1942 pp. 100-1 as quoted in Peter
Groenewegen, A Soaring Eagle: Alfred Marshall, 1842-1924, pp. 434-5))
"Unlike physics, ... such parts of the bare bones of economic theory as
are
expressible in mathematical form are extremely easy compared with the
economic interpretation of the complex and incompletely known facts of
experience, [Footnote: "Professor Planck, of Berlin, the famous
originator
of the Quantum Theory, once remarked to me that in early life he had
thought
of studying economics, but had found it too difficult! Professor Planck
could easily master the whole corpus of mathematical economics in a few
days. He did not mean that! But the amalgam of logic and intuition
and the
wide knowledge of the facts, most of which are not precise, which is
required for economic interpretation in its highest form is, quite
truly,
overwhelmingly difficult for those whose gift mainly consists in the
power
to imagine and pursue to their furthest points the implications and
prior
conditions of comparatively simple facts which are known with a high
degree
of precision."] and lead one but a very little way towards establishing
useful results." (Keynes, X, p. 186)
Like Schumpeter, Keynes contrasts Marshall's approach with that aspect
of
Mill with which you appear to claim both Marshall and Keynes should be
identified. He does this in the context of offering a psychological
explanation for Marshall's inability to make his actions fully conform
to
his beliefs about the ultimate nature of economics.
"he [Marshall] was too little willing to cast his half-baked bread on
the
waters, to trust in the efficacy of the co-operation of many minds, and
to
let the big world draw from him what sustenance it could. Was he not
attempting, contrary to his own principles, to achieve an impossible
finality? An economic treatise may have great educational value.
Perhaps
we should have one treatise, as a pièce de résistance, for each
generation.
But in view of the transitory character of economic facts, and the
bareness
of economic principles in isolation, does not the progress and the daily
usefulness of economic science require that pioneers and innovators
should
eschew the treatise and prefer the pamphlet or the monograph? ... Did
not
Mill, in achieving by his peculiar gifts a successful treatise, do more
for
pedagogics than for science, and end by sitting like an Old Man of the
Sea
on the voyaging Sinbads of the next generation? Economists must leave to
Adam Smith alone the glory of the quarto, must pluck the day, fling
pamphlets into the wind, write always *sub specie temporis*, and achieve
immorality by accident, if at all.
"Moreover, did not Marshall, by keeping his wisdom at home until he
could produce it fully clothed, mistake, perhaps, the true nature of
his own
special gift? 'Economics', he said, in the passage quoted above, 'is
not a
body of concrete truth, but an engine for the discovery of concrete
truth.'
This engine, as we employ it to-day, is largely of Marshall's
creation. He
put it in the hands of his pupils long before he offered it to the
world.
The building of this engine was the essential achievement of Marshall's
peculiar genius. Yet he hankered greatly after the 'concrete truth'
which
he had disclaimed and for the discovery of which he was not specially
qualified." (X, pp. 198-9)