Main trends of research in the social and human ... - unesdoc - Unesco

522 Jean Piaget
family organization, economic life, myths and language. And this problem of
logic in tribal civilizations has by no means been solved; indeed, it requires not
only detailed psychological experimentation, which has not yet been developed
in this comparative form, but also careful comparison, in each society, between
practical or technical intelligence and discursive or merely verbal thought.
Linguistics provides us with basic material concerning the oral or written ex-
pression of cognitive structures such as numeration systems, classifications,
systems of relations and so on.
The two main branches of science, in connexion with the formation of the
tools of cognition - the sociology of knowledge and genetic psychology - are
complementary. The socio-genesis of knowledge shows us both the progressive,
co-operative construction of movements of ideas as they are transmitted and
developed, from one generation to another, and the effects of the numerous
obstacles that slow down or divert the progress of ideas. The historical sociol-
ogy of knowledge, for instance, which is bound to depend increasingly on the
history of ideas, sciences and techniques, should be able to throw light on phe-
nomena as momentous as the Greek miracle or the decay of Greek knowledge
in the time of Alexander, and it will at once be seen that this last problem, for
which the human sciences should provide some solution, cannot be solved
except by comparing economic and social factors with the inner evolution of
concepts and principles whose initial imperatives might furnish reasons for their
subsequent sterility.
Genetic psychology and comparative psychology (including ethology) are
far from dealing with such central facts, but their great advantage is that they
are concerned with series that are not so incomplete and, most important, can
be reproduced at will. An example of this is the construction of whole or ‘natu-
ral’ numbers. All the data collected by the foregoing branches of knowledge
show that the elaboration of such numbers is common in the different civiliza-
tions, and also that the levels reached differ widely, but none of these facts show
us the construction itself; we know only its results. On the other hand, although
a young child is surrounded by adults who teach him to count, and although
the form of expression he uses includes a system of numeration, yet one can
easily, by means of carefully-planned experiments, go back to stages where the
term ‘numbers’ cannot yet be used because numerical sets are not conserved
(5 items are not 5 if their arrangement in space is changed, and so on), and by
starting at such stages it is possible to observe the mechanism by which number
is constituted through purely logical operations, yet by making a fresh synthesis
of the operations of inclusion and arrangement in order. Such information, there-
fore, throws light on ethnographic and historical data, which would be super-
fluous if we could go back to the mental activity of prehistoric man - but that,
unhappily, is impossible in a sphere such as the origin of number. On the other
hand, information of this kind gives rise to fresh problems of logic, and not
only has this genetic construction been formalized (J. B. Grize and G. Granger),
but it has also been shown that, implicitly but necessarily, its essential aspects
were found in all the models elaborated by logicians concerning the transition
from classes or relations to numbers. Thirdly, it is instructive to compare such