It is impossible to fix or decide by inner or outer evidence the precise order of production, much less of composition, which critics of the present or the past may have set their wits to verify in vain; but it is quite possible to show that the work of Shakespeare is naturally divisible into classes which may serve us to distinguish and determine as by landmarks the several stages or periods of his mind and art. Of these the three chief periods or stages are so unmistakably indicated by the mere text itself, and so easily recognisable by the veriest tiro in the school of Shakespeare, that even were I as certain of being the first to point them out as I am conscious of having long since discovered and verified them without assistance or suggestion from any but Shakespeare himself.