We learn from our Greek grammars that the second syllable in δείκνῡμι is long, but in the plural, δείκνῠμεν, it is short. This cannot be by accident, and we may observe the same change in δάμνημι and δάμναμεν, and similar words. Nothing, however, but a study of Sanskrit would have enabled us to discover the reason of this change, which is really the accent in its most primitive working, such as we can watch it in the Vedic Sanskrit, where it produces exactly the same change, only with far greater regularity and perspicuity. Why, again, do we say in Greek, οἶδα, I know, but ἴσ-μεν, we know? Why τέτληκα, but τέτλαμεν? Why μέμονα, but μέμαμεν? There is no recollection in the minds of the Greeks of the motive power that was once at work, and left its traces in these grammatical convulsions; but in Sanskrit we still see, as it were, a lower stratum of grammatical growth, and we can there watch the regular working of laws which required these changes, and which have left their impress not only on Greek, but on Sanskrit, and even on German. The same necessity which made Homer say οἶδα and ἴδμεν, and the Vedic poet +véda+ and +vidmás+, still holds good, and makes us say in German, _Ich weiss_, I know, but _wir wissen_, we know. All this becomes clear and intelligible by the light of Comparative Grammar; anomalies vanish, exceptions prove the rule, and we perceive more plainly every day how in language, as elsewhere, the conflict between the freedom claimed by each individual and the resistance offered by the community at large, establishes in the end a reign of law most wonderful, yet perfectly rational and intelligible.