book
again_. And perhaps in another fortnight I had come to
the old difficulty with impetus enough to get over it. Or
perhaps not. I have several books that I have begun over and
over again.

My second hint shall be--Never leave an unsolved difficulty
_behind_. I mean, don't go any further in that book
till the difficulty is conquered. In this point, Mathematics
differs entirely from most other subjects. Suppose you are
reading an Italian book, and come to a hopelessly obscure
sentence--don't waste too much time on it, skip it, and go
on; you will do very well without it. But if you skip a
_mathematical_ difficulty, it is sure to crop up again:
you will find some other proof depending on it, and you will
only get deeper and deeper into the mud.

My third hint is, only go on working so long as the brain is
_quite_ clear. The moment you feel the ideas getting
confused leave off and rest, or your penalty will be that
you will never learn Mathematics _at all_!

Two more letters to the same friend are, I think, deserving of a place
here:--

Eastbourne, _Sept_. 25, 1885.

My dear Edith,--One subject you touch on--"the Resurrection
of the Body"--is very interesting to me, and I have given it
much thought (I mean long ago). _My_ conclusion was to
give up the _literal_ meaning of the _material_
body altogether. _Identity_, in some mysterious way,
there evidently is; but there is no resisting the scientific
fact that the actual _material_ usable for
_physical_ bodies has been used over and over again--so
that each atom would have several owners. The mere solitary
fact of the existence of _cannibalism_ is to my mind a
sufficient _reductio ad absurdum_ of the theory that
the particular set of atoms I shall happen to own at death
(changed every seven years, they say) will be mine in the
next life--and all the other insuperable difficulties (such
as people born with bodily defects) are swept away at once
if we accept S. Paul's "spiritual body," and his simile of
the grain of corn. I have read very little of "Sartor
Resartus," and don't know the passage you quote: but I
accept the idea of the material body being the "dress" of
the spiritual--a dress needed for material life.

Ch. Ch., _Dec_. 13, 1885.

Dear Edith,--I have been a severe sufferer from
_Log