heir ideas
directly from the real world, and to form them in keeping with it--but
not to get them from elsewhere, as from books, fables, or what others
have said--and then later to make use of such ready-made ideas in real
life. The result will be that their heads are full of chimeras and that
some will have a wrong comprehension of things, and others will
fruitlessly endeavour to remodel the world according to those chimeras,
and so get on to wrong paths both in theory and practice. For it is
incredible how much harm is done by false notions which have been
implanted early in life, only to develop later on into prejudices; the
later education which we get from the world and real life must be
employed in eradicating these early ideas. And this is why, as is
related by Diogenes Laertius, Antisthenes gave the following answer:
[Greek: erotaetheis ti ton mathaematon anankaiotaton, ephae, "to kaka
apomathein."] (_Interrogatus quaenam esset disciplina maxime necessaria,
Mala, inquit, dediscere_.)

* * * * *

Children should be kept from all kinds of instruction that may make
errors possible until their sixteenth year, that is to say, from
philosophy, religion, and general views of every description; because it
is the errors that are acquired in early days that remain, as a rule,
ineradicable, and because the faculty of judgment is the last to arrive
at maturity. They should only be interested in such things that make
errors impossible, such as mathematics, in things which are not very
dangerous, such as languages, natural science, history, and so forth; in
general, the branches of knowledge which are to be taken up at any age
must be within reach of the intellect at that age and perfectly
comprehensible to it. Childhood and youth are the time for collecting
data and getting to know specially and thoroughly individual and
particular things. On the other hand, all judgment of a general nature
must at that time be suspended, and final explanations left alone. One
should leave the faculty of judgment alone, as it only comes with
maturity and experience, and also take care that one does not anticipate
it by inculcating prejudice, when it will be crippled for ever.

On the contrary, the memory is to be specially exercised, as it has its
greatest strength and tenacity in youth; however, what has to be
retained must be chosen with the most careful and scrupulous
consideration. For as it is what we h