they both owed to Barrow, is still a matter for conjecture.
It is certainly true that Newton had developed his formu-
lation of the calculus, the method of 'fluxions', as early as
1665, though it was not published till many years later,
to 'avoid publicity'. An odd motive to modern ears!
Leibniz was probably right when he spoke of himself and
Barrow as 'contemporaries in these discoveries'. All the
mathematicians of the time were working on similar prob-
lems, and all knew the work that had been done earlier
on the summation of infinitesimal quantities. To Leibniz,
however, we must give the credit for using the infinite-
simals as differences and for developing a notation which
was so much the most convenient that it is still in use at
the present day. If the fundamental notions of the calculus
were in the air, then he who manages to express them in
the most fruitful way has, perhaps, the best claim to be
called the inventor.

It would appear from this short statement that not
many of Leibniz's practical schemes bore fruit. Moreover,
many modern philosophers think that his metaphysical
doctrines should either be interpreted as statements be-
longing to logic or disregarded as idle speculation. Never-
theless, there is no doubt that Leibniz will always hold an
honoured place as the inventor of the infinitesimal calcu-
lus and the founder of Symbolic Logic.

The last years of Leibniz's life were the least happy. The
two Electresses, Sophia and Sophia Charlotte, died in
1705 and 1714. In 1714 also, George of Hanover was called
to the English throne. He seems to have disliked Leibniz,
and when the Court moved to London, Leibniz was not
allowed to accompany it. He was told to attend to his
duties as Librarian. He was in disfavour with the clergy,
who called him 'Lövenix', believer in nothing, and prob-
ably as a result of his reputation as a disbeliever, he was
generally unpopular. His health was now beginning to

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