An introductory text-book of logic - Mellone, Sydney - Rare Books at ...

226 THE GENERAL NATURE OF INDUCTION.
law as would, if we suppose
a certain result."
some stated conditions
present, produce
We have seen (ch. V.)
that the major premise in the
typical syllogism is a general principle of this kind.
Hence we get the natural meaning of the major when
it is expressed not as a categorical universal but as a
hypothetical proposition. Its application to a particular
case may be thus illustrated :
Law of Nature : If anything is M it is P ;
Particular fact : S
Application S
is M ;
and conclusion :
is P.
This may be illustrated by a few concrete examples.
(1) Whatever lengthens the pendulum lengthens the path
in which it swings ;
Heat lengthens the ;
pendulum
Therefore heat lengthens the path in which it swings.
(2) If a body moves in a regular orbit round a centre, it
tends to move farther from the centre of revolution ;
A body on the surface of the earth moves in a regular
orbit round the centre of the earth ;
Therefore it tends to move farther from the centre.
(3) If the speed of the moving body is increased, the cen
trifugal tendency is greater.
The rate of motion of a body on the earth s surface is
greater at the equator than at higher latitudes ;
Therefore the centrifugal tendency generated in it by
the earth s motion is greater at the equator than at
higher latitudes.
From this it follows that a body weighs least at the equator,
and the weight increases as the latitude increases. This
purely deductive reasoning is confirmed by experiments with
delicate spring balances or : pendulums the downward pull
of a body is least at the equator.
Observe the premise
"
"
if is anything M it is P more
particularly. Regarded as a logical proposition,
it
states that the antecedent is the reason of the con-