ality of Cause and Effect; and this, in the
above example, the Chemist determines by showing that, instead of the
oxygen and wax that have disappeared during combustion, an equivalent
weight of carbon dioxide, water, etc., has been formed.

Here, then, we have all the marks of causation; but in the ordinary
judgments of life, in history, politics, criticism, business, we must
not expect such clear and direct proofs; in subsequent chapters it will
appear how different kinds of evidence are combined in different
departments of investigation.

Sec. 7. The Inductive Canons, to be explained in the next chapter, describe
the character of observations and experiments that justify us in drawing
conclusions about causation; and, as we have mentioned, they are derived
from the principle of Causation itself. According to that principle,
cause and effect are invariably, immediately and unconditionally
antecedent and consequent, and are equal as to the matter and energy
embodied.

Invariability can only be observed, in any of the methods of induction,
by collecting more and more instances, or repeating experiments. Of
course it can never be exhaustively observed.

Immediacy, too, in direct Induction, is a matter for observation the
most exact that is possible.

Succession, or the relation itself of antecedent and consequent, must
either be directly observed (or some index of it); or else ascertained
by showing that energy gained by one phenomenon has been lost by
another, for this implies succession.

But to determine the unconditionality of causation, or the
indispensability of some condition, is the great object of the methods,
and for that purpose the meaning of unconditionality may be further
explicated by the following rules for the determination of a Cause.

A. QUALITATIVE DETERMINATION

_I.--For Positive Instances._

To prove a supposed Cause: (a) Any agent whose introduction among
certain conditions (without further change) is followed by a given
phenomenon; or, (b) whose removal is followed by the cessation (or
modification) of that phenomenon, is (so far) the cause or an
indispensable condition of it.

To find the Effect: (c) Any event that follows a given phenomenon, when
there is no further change; or, (d) that does not occur when the
conditions of a former occurrence are exactly the same, except for the
absence of that phenomenon, is the effect of it (or is dependent on
it).

_II.--For Negative Instan