and consequently universal validity by saying that we can see no
ground for attributing any other sort of knowledge to other rational
beings, if this reasoning were valid, our ignorance would do more
for the enlargement of our knowledge than all our meditation. For,
then, on this very ground that we have no knowledge of any other
rational beings besides man, we should have a right to suppose them to
be of the same nature as we know ourselves to be: that is, we should
really know them. I omit to mention that universal assent does not
prove the objective validity of a judgement (i.e., its validity as a
cognition), and although this universal assent should accidentally
happen, it could furnish no proof of agreement with the object; on the
contrary, it is the objective validity which alone constitutes the
basis of a necessary universal consent.

{PREFACE ^paragraph 30}

Hume would be quite satisfied with this system of universal
empiricism, for, as is well known, he desired nothing more than
that, instead of ascribing any objective meaning to the necessity in
the concept of cause, a merely subjective one should be assumed, viz.,
custom, in order to deny that reason could judge about God, freedom,
and immortality; and if once his principles were granted, he was
certainly well able to deduce his conclusions therefrom, with all
logical coherence. But even Hume did not make his empiricism so
universal as to include mathematics. He holds the principles of
mathematics to be analytical; and if his were correct, they would
certainly be apodeictic also: but we could not infer from this that
reason has the faculty of forming apodeictic judgements in
philosophy also- that is to say, those which are synthetical
judgements, like the judgement of causality. But if we adopt a