The supplements to this fourth book would be very considerable if it were
not that two of its principal subjects which stand specially in need of
being supplemented—the freedom of the will and the foundation of
ethics—have, on the occasion of prize questions being set by two
Scandinavian Academies, been fully worked out by me in the form of a
monograph, which was laid before the public in the year 1841 under the
title, “The Two Fundamental Problems of Ethics.” Accordingly I assume an
acquaintance on the part of my readers with the work which has just been
mentioned, just as unconditionally as in the supplements to the second
book I have assumed it with regard to the work “On the Will in Nature.” In
general I make the demand that whoever wishes to make himself acquainted
with my philosophy shall read every line of me. For I am no voluminous
writer, no fabricator of compendiums, no earner of pecuniary rewards, not
one whose writings aim at the approbation of a minister; in a word, not
one whose pen is under the influence of personal ends. I strive after
nothing but the truth, and write as the ancients wrote, with the sole
intention of preserving my thoughts, so that they may be for the benefit
of those who understand how to meditate upon them and prize them.
Therefore I have written little, but that little with reflection and at
long intervals, and accordingly I have also confined within the smallest
possible limits those repetitions which in philosophical works are
sometimes unavoidable on account of the connection, and from which no
single philosopher is free; so that by far the most of what I have to say
is only to be found in one place. On this account, then, whoever wishes to
learn from me and understand me must leave nothing unread that I have
written. Yet one can judge me and criticise me without this, as experience
has shown; and to this also I further wish much pleasure.
Meanwhile the space gained by the said elimination of two important
subjects will be very welcome to us. For since those explanations, which
every man has more at heart than anything else, and which therefore in
every system, as ultimate results, form the apex of its pyramid, are also
crowded together in _my_ last book, a larger space will gladly be granted
to every firmer proof or more accurate account of these. Besides this we
have been able to discuss here, as belonging to the doctrine of the
“assertion of the will to live,” a question which in our fourth book
itself remained untouched, as it was also entirely neglected by all
philosophers before me: it is the inner significance and real nature of
the sexual love, which sometimes rises to a vehement passion—a subject
which it would not have been paradoxical to take up in the ethical part of
philosophy if its importance had been known.