The system becomes more coherent as it is further extended. The elements which we require for explaining a new class of facts are already contained i… - William Whewell

It is a test of true theories not only to account for but to predict phenomena.

According to the technical language of old writers, a thing and its qualities are described as subject and attributes; and thus a man’s faculties and acts are attributes of which he is the subject. The mind is the subject in which ideas inhere. Moreover, the man’s faculties and acts are employed upon external objects; and from objects all his sensations arise. Hence the part of a man’s knowledge which belongs to his own mind, is subjective: that which flows in upon him from the world external to him, is objective.

And so no force however great can stretch a cord however fine into an horizontal line which is accurately straight.