[…] as language is incapable of expressing all qualities, even of material things, by one word; being obliged to indicate one quality only; how could it be constantly possible fully to convey the finer shades of modal and temporal meaning? And if languages here likewise bend to the necessity of sometimes expressing a part, how can the philologist always determine with certainty, what part is expressed, and what supplied by the usage of language? […] the usage of language is despotic, arbitrarily employing its means, without control.
- Bopp (1820), a pag.27-28

The Sanskrit language is in general much more regular than the Greek, and particularly the change of vowels is entirely founded in nature, there is no arbitrary usage of language.
- Bopp (1820), a pag.40