That the effort of the agnostic contention has been great, and on the whole salutary, few would deny. Spencer's own later work shows that his declaration, that the absolute which lies behind the universe is unknowable, is to be taken with considerable qualification. It is only a relative unknowableness which he predicates. Moreover, before Spencer's death, the doctrine of evolution had made itself profoundly felt in the discussion of all aspects of life, including that of religion. There seemed no longer any reason for the barrier between science and religion which Spencer had once thought requisite. The epithet agnostic, as applied to a certain attitude of scientific mind, is just, as over against excessive claims to valid knowledge made, now by theology and now by speculative philosophy. It is hardly descriptive in any absolute sense. Spencer had coined the rather fortunate illustration which describes science as a gradually increasing sphere, such that every addition to its surface does but bring us into more extensive contact with surrounding nescience. Even upon this illustration Ward has commented that the metaphor is misleading. The continent of our knowledge is not merely bounded by an ocean of ignorance. It is intersected and cut up by straits and seas of ignorance. The author of _Ecce Coelum_ has declared: 'Things die out under the microscope into the same unfathomed and, so far as we can see, unfathomable mystery, into which they die off beyond the range of our most powerful telescope.' This sense of the circumambient unknown has become cardinal with the best spirits of the age. Men have a more rigorous sense of what constitutes knowledge. They have reckoned more strictly with the methods by which alone secure and solid knowledge may be attained. They have undisguised scepticism as to alleged knowledge not arrived at in those ways. It was the working of these motives which gave to the labours of the middle of the nineteenth century so prevailingly the aspect of denial, the character which Carlyle described as an everlasting No. This was but a preparatory stage, a retrogression for a new and firmer advance.