MA177---What to look for in Newton and Berkeley
Monday we'll discuss Newton's ``Lemma II'' and Berkeley's ``The Analyst.''
Here are a few things to look for as you read (or re-read) these texts.
- What Newton calls a ``genitum'' is just a product of powers
where there can be lots of factors and the
exponents are of any kind. The point of the Lemma is to determine
the fluxion (or the differential) of such a quantity.
- What Newton calls a ``moment'' is essentially a Leibniz-style
differential: it's the amount an object ``wants to change'' when it
just begins to change. In the ``o'' notation, it's , in the
sense that as time moves from t to t+o, the
fluent x ``wants to'' become (of course, this isn't
exactly right, but it gets closer to being right as the increment
o gets closer to zero...).
- The most important part of the proof is ``Case 1'' on page 2. Make
sure you understand. Compare with Leibniz's rule for the
differential of a product.
- In Cases 2-6, Newton basically uses Case 1 over and over again to
establish more complicated cases.
- Don't worry about the Corollaries on page 3.
- In ``The Analyst,'' Berkeley starts by giving his purpose in writing;
what is it?
- Berkeley then tries to figure out what is meant by ``moment,''
``fluxion,'' and so on. What does he conclude?
- Notice that pages 7/8 were bound in backwards, so page 8 comes before
page 7!
- In sections 9-12, Berkeley discusses Newton's argument in Case 1 of
``Lemma II'' and its consequences. What does he make of Newton's
argument?
- In sections 13-16, Berkeley goes over the bit we did in class to
compute the fluxion of . What is his
argument?
- Section 20 is important. What is Berkeley's main position?
- How does Berkeley explain the fact that the calculus works?
Fernando Q. Gouvea
Fri Nov 14 09:40:22 EST 1997