38.

There is nothing which deceives us as much as our own judgement.

39.

The greatest deception which men incur proceeds from their opinions.

40.

Avoid the precepts of those thinkers whose reasoning is not confirmed
by experience.

[Sidenote: Intelligence of Animals]

41.

Man discourseth greatly, and his discourse is for the greater part
empty and false; the discourse of animals is small, but useful and
true: slender certainty is better than portentous falsehood.

42.

What is an element? It is not in man's power to define the quiddity of
the elements, but a great many of their effects are known.

43.

That which is divisible in fact is divisible in potentiality also; but
not all quantities which are divisible in potentiality are divisible in
fact.

[Sidenote: Infinity incomprehensible]

44.

What is that thing which is not defined and would {16} not exist if it
were defined? It is infinity, which if it could be defined would be
limited and finite, because that which can be defined ends with the
limits of its circumference, and that which cannot be defined has no
limits.

45.

O contemplators of things, do not pride yourselves for knowing those
things which nature by herself and her ordination naturally conduces;
but rejoice in knowing the purposes of those things which are
determined by your mind.

[Sidenote: Insoluble Questions]

46.

Consider, O reader, how far we can lend credence to the ancients who
strove to define the soul and life,--things which cannot be proved;
while those things which can be clearly known and proved by experience
remained during so many centuries ignored and misrepresented! The eye,
which so clearly demonstrates its functions, has been up to my time
defined in one manner by countless authorities; I by experience have
discovered another definition.

[Sidenote: Beauty of Nature's Inventions]

47.

Although human ingenuity may devise various inventions which, by the
help of various instruments, answer to one and the same purpose, yet
{17} will it never discover any inventions more beautiful, more simple
or more practical than those of nature, because in her inventions there
is nothing lacking and nothing superfluous; and she makes use of no
counterpoise when she constructs the limbs of animals in such a way as
to correspond to the motion of their bodies, but she puts into them the
soul of the body. This is not the proper place for this