The importance of biography for the study of history can hardly be
overrated. In a sense it is true that history should be like the law
and 'care not about very small things'; concerning itself not so much
with individual personality as with fundamental causes affecting the
rise and fall of nations or the development of mental outlook from one
age to another. But even if this be conceded, we still must not forget
that the course of history is worked out by individuals, who, in spite
of the accidental condensation that the needs of human life thrust
upon them, are isolated at the last and alone--for no man may deliver
his brother. In consequence, it is only in periods when the stream of
personal record flows wide and deep that history begins to live, and
that we have a chance to view it through the eyes of the actors
instead of projecting upon it our own fancies and conceptions.

One of the features that makes the study of the Renaissance so
fascinating is that in that age the stream of personal record, which
had been driven underground, its course choked and hidden beneath the
fallen masonry of the Roman Empire, emerges again unimpeded and flows
in ever-increasing volume. For reconstruction of the past we are no
longer limited to charters and institutions, or the mighty works of
men's hands. In place of a mental output, rigidly confined within
unbending modes of thought and expression, we have a literature that
reflects the varied phases of human life, that can discard romance and
look upon the commonplace; and instead of dry and meagre chronicles,
rarely producing evidence at first hand, we have rich store of memoirs
and private letters, by means of which we can form real pictures of
individuals--approaching almost to personal acquaintance and
intimacy--and regard the same events from many points of view, to
perception of the circumstances that 'alter cases'.