ABSTRACT
The only phenomena to which those of intelligence are allied, are the phenomena of vital activity in its lower forms; and to these their alliance is close. Though people commonly regard mental and bodily life as distinct, it needs only to ascend somewhat above the ordinary point of view, to see that they are but sub-divisions of life in general; and that no line of demarcation can be drawn between them, otherwise than arbitrarily. The more general is any truth, the more vague it is. The greater the range and the more diverse the character of the phenomena, the less apparent relation will a proposition which is true of them all, have to each. Little connection is visible between the axiom—“Things that are equal to the same thing are equal to one another,” and the theorems of Euclid.
