minor premise, since it deals with a particular man. The third is the conclusion,
in which a new relation is discovered between Socrates and mortality.
This form of reasoning is deductive, that is, it proceeds from the general to the
particular. Much of our reasoning is an abbreviated form of the syllogism, and
will readily expand into it. For instance, we say, "It will rain tonight, for there is
lightning in the west." Expanded into the syllogism form it would be, "Lightning
in the west is a sure sign of rain; there is lightning in the west this evening;
therefore, it will rain tonight." While we do not commonly think in complete
syllogisms, it is often convenient to cast our reasoning in this form to test its
validity. For example, a fallacy lurks in the generalization, "Lightning in the
west is a sure sign of rain." Hence the conclusion is of doubtful validity.
Induction.—Deduction is a valuable form of reasoning, but a moment's
reflection will show that something must precede the syllogism in our reasoning.
The major premise must be accounted for. How are we able to say that all men
are mortal, and that lightning in the west is a sure sign of rain? How was this
general truth arrived at? There is only one way, namely, through the observation
of a large number of particular instances, or through induction.
Induction is the method of proceeding from the particular to the general. Many
men are observed, and it is found that all who have been observed have died
under a certain age. It is true that not all men have been observed to die, since
many are now living, and many more will no doubt come and live in the world
whom we cannot observe, since mortality will have overtaken us before their
advent. To this it may be answered that the men now living have not yet lived up
to the limit of their time, and, besides, they have within them the causes working
whose inevitable effect has always been and always will be death; likewise with
the men yet unborn, they will possess the same organism as we, whose very
nature necessitates mortality. In the case of the premonitions of rain, the
generalization is not so safe, for there have been exceptions. Lightning in the
west at night is not always followed by rain, nor can we find inherent causes as
in the other case which necessitates rain as an effect.
The Necessity for Broad Induction.—Thus it is seen that our generalizations,
or major premises, are of all degrees of validity. In the case of some, as the
mortality of man, millions of cases have been observed and no exceptions found,
but on the contrary, causes discovered whose operation renders the result
inevitable. In others, as, for instance, in the generalization once made, "All
cloven-footed animals chew their cud," not only had the examination of