Until you have mastered the fundamental difference, in kind, between the
reason and the understanding as faculties of the human mind, you cannot
escape a thousand difficulties in philosophy. It is pre-eminently the
_Gradus ad Philosophiam_.
* * * * *
The general harmony between the operations of the mind and heart, and the
words which express them in almost all languages, is wonderful; whilst the
endless discrepancies between the names of _things_ is very well deserving
notice. There are nearly a hundred names in the different German dialects
for the alder-tree. I believe many more remarkable instances are to be
found in Arabic. Indeed, you may take a very pregnant and useful
distinction between _words_ and mere arbitrary _names of things_.
_May 15. 1830._