Nature as a machine, governed by changeless causal law, is necessary to thought.
It is chiefly known from the causal relation of one of its species of the most serious of vine-diseases.
It is only gradually that there appears any recognition of a spiritual principle exercising a modifying or causal influence over inert matter.
There is thus causal necessity for Eternal Mind, or what we call " God."
Nevertheless he believes that, when we can apply measures to the combination of empirical appearances, then we can apply the logical principle as causal law to this combination, and say that one appearance is the cause of another, thus adding a notion of causality not contained in the actual observations, but specializing the general notion of causality.