degrees of, in series of animals and in man, iii. [29], [30];

parsimony of nature in imparting, iii. [20];

limitation of, to phenomena, iii. [21-29];

imperfections of, ii. 330-344.

Interesting, distinguished from beautiful, i. 229.

Ionic school, i. 33.

Irritability as objectification of will, ii. 472 seq.;

its connection with blood, ii. 478.

Isaiah ii. 437.

Islamism, iii. [423], [446].