een successful in accomplishing those objects.

That all inference to the unobserved is founded on facts, on the
data of experience, need not be postulated. It is enough to say that
Inductive Logic is concerned with inference in so far as it is founded
on the data of experience. But inasmuch as all the data of experience
are not of equal value as bases of inference, it is well to begin with
an analysis of them, if we wish to take a comprehensive survey of the
various modes of inference and the conditions of their validity.

[Footnote 1: Hamilton's _Reid_, p. 712.]

[Footnote 2: The _Novum Organum_ was never completed. Of
the nine heads of special aids to the intellect in the final
interpretation he completed only the first, the list of
Prerogative Instances.]

[Footnote 3: _Sylva Sylvarum_, Century I, 24.]

[Footnote 4: _Sylva Sylvarum_, Century I, 5.]

CHAPTER I.

THE DATA OF EXPERIENCE AS GROUNDS OF INFERENCE OR RATIONAL BELIEF.

If we examine any of the facts or particulars on which an inference
to the unobserved is founded, we shall find that they are not isolated
individuals or attributes, separate objects of perception or thought,
but relations among things and their qualities, constituents, or
ingredients.

Take the "particular" from which Mill's village matron inferred, the
fact on which she based her expectation of a cure for her neighbour's
child. It is a relation between things. We have the first child's
ailment, the administration of the drug, and the recovery, a series of
events in sequence. This observed sequence is the fact from which she
is said to infer, the datum of experience. She expects this sequence
to be repeated in the case of her neighbour's child.

Similarly we shall find that, in all cases where we infer, the
facts are complex, are not mere isolated things, but relations among
things--using the word thing in its widest sense--relations which we
expect to find repeated, or believe to have occurred before, or to be
occurring now beyond the range of our observation. These relations,
which we may call coincidences or conjunctions, are the data of
experience from which we start in our beliefs or inferences about the
unexperienced.

The problem of Inductive Logic being to determine when or on what
conditions such beliefs are rational, we may begin by distinguishing
the data of coincidence or conjunction accordingly. There are certain
coincidences that