rinciples of the Philosophy of the Expansive and Contractive
Forces ... By Robert Greene,[279] M.A., Fellow of Clare Hall.
Cambridge, 1727, folio.

Sanderson[280] writes to Jones,[281] "The gentleman has been reputed mad
for these two years last past, but never gave the world such ample
testimony of it before." This was said of a former work of Greene's, on
solid geometry, published in 1712, in which he gives a quadrature.[282] He
gives the same or another, I do not know which, in the present work, in
which the circle is 3-1/5 diameters. This volume is of 981 good folio
pages, and treats of all things, mental and material. The author is not at
all mad, only wrong on {136} many points. It is the weakness of the
orthodox follower of any received system to impute insanity to the solitary
dissentient: which is voted (in due time) a very wrong opinion about
Copernicus, Columbus, or Galileo, but quite right about Robert Greene. If
misconceptions, acted on by too much self-opinion, be sufficient evidence
of madness, it would be a curious inquiry what is the least per-centage of
the reigning school which has been insane at any one time. Greene is one of
the sources for Newton being led to think of gravitation by the fall of an
apple: his authority is the gossip of Martin Folkes.[283] Probably Folkes
had it from Newton's niece, Mrs. Conduitt, whom Voltaire acknowledges as
_his authority_.[284] It is in the draft found among Conduitt's papers of
memoranda to be sent to Fontenelle. But Fontenelle, though a great retailer
of anecdote, does not mention it in his _eloge_ of Newton; whence it may be
suspected that it was left out in the copy forwarded to France. D'Israeli
has got an improvement on the story: the apple "struck him a smart blow on
the head": no doubt taking him just on the organ of causality. He was
"surprised at the force of the stroke" from so small an apple: but then the
apple had a mission; Homer would have said {137} it was Minerva in the form
of an apple. "This led him to consider the accelerating motion of falling
bodies," which Galileo had settled long before: "from whence he deduced the
principle of gravity," which many had considered before him, but no one had
_deduced anything from it_. I cannot imagine whence D'Israeli got the rap
on the head, I mean got it for Newton: this is very unlike his usual
accounts of things. The story is pleasant and possible: its only defect is
that various writings, well kn