There can be no perfect way, for classification presupposes that a thing
has absolute limits whereas there is nothing that does not partake of the
universal infinity—nothing whose boundaries do not vary. Everything is
one thing at one time and in some respects, and another at other times
and in other respects. We want a new mode of measurement altogether; at
present we take what gaps we can find, set up milestones, and declare
them irremovable. We want a measure which shall express, or at any rate
recognise, the harmonics of resemblance that lurk even in the most
absolute differences and vice versa.