le for new scientific statements. If we should seek to
establish its reality beyond those limits we are at once confronted by
a dilemma, both poles of the antagonism come into conflict with their
opposite; truth becomes error and error becomes truth. Let us take,
for example, the well-known Boyle's law, according to which, the
temperature remaining the same, the volume of the gas varies as the
pressure to which it is subjected. Regnault discovered that this law
does not apply in certain cases. If he had been a realist-philosopher
he would have been obliged to say, "Boyle's law is mutable, therefore
it does not possess absolute truth, therefore it is untrue, therefore
it is false." He would thus have made a greater error than that which
was latent in Boyle's law, his little particle of truth would have
been drowned in a flood of error; he would in this way have elaborated
his correct result into an error compared with which Boyle's law with
its particle of error fastened to it would have appeared as the truth.
Regnault, scientist as he was, did not trouble himself with such
childish performances. He investigated further and found that Boyle's
law is only approximately correct, having no validity in the case of
gases which can be made liquid by pressure when the pressure
approaches the point where liquefaction sets in. Boyle's law therefore
is shown only to be true within specific bounds. But is it absolute, a
final truth of last instance within specific bounds? No physicist
would say so. He would say that it is correct for certain gases and
within certain limits of pressure and temperature, and even then
within these somewhat narrow limits he would not exclude the
possibility of a still narrower limitation or change in application as
the result of further investigation. This is how final truths of last
instance stand in physics, for example. Really scientific works as a
rule avoid such dogmatic expressions as truth and error, but they are
constantly cropping up in works like the Philosophy of Reality, where
mere loose talking vaunts itself the supreme result of sovereign
thought.

But a naive reader may say, "Where has Herr Duehring expressly stated
that the content of his philosophy of reality is final truth of the
last instance?" Well, for example, in his dithyramb on his system
which we quoted above, and again where he says "Moral truths as far as
they are known are as sound as those of mathematics." Does not Herr
Du