AGNOSTICISM IN HUXLEY'S HUME. 483 



two straight lines, we perceive, without any mediate proof, that they 

 can not inclose a space. Our commentator on Hume has equally mis- 

 understood the nature of this necessity. He speaks of three kinds of 

 necessity. The first is one merely requiring the consistent use of 

 language : " The necessary truth A = A means that the perception 

 which is called A shall always be called A." This throws no light on 

 our convictions. The second, " The necessary truth that ' two straight 

 lines can not inclose a space,' means that we have no memory, and can 

 form no expectation of their so doing." The instance he gives is a 

 good example of an intuitive truth seen at once, and necessarily be- 

 lieved ; but it surely implies vastly more than merely that we have no 

 memory, and can form no expectation of two straight lines inclosing 

 a space ; it means that we perceive that, from the very nature of 

 things, two such lines can not inclose a space. He has a third case 

 of necessity, " The denial of the necessary truth that the thought now 

 in my mind exists, involves the denial of consciousness." This is also 

 an example of a self-evident, necessary truth, but it is so because we 

 have an immediate knowledge of ourselves as existing. 



6. Hume's doctrine of causation takes a double form ; the one ob- 

 jective, the other subjective. These two are intimately connected, and 

 yet they should be carefully separated. Hume held that objective 

 causation is only invariable antecedence and consequence. This is a 

 doctrine contradicted both by metaphysical and physical science. It 

 seems very clear to me that our intuitions, looking on objects, declare 

 that they have power. This is implied in the axiom that we know 

 objects as having properties ; and what are properties but powers ? 

 Then modern science has established the doctrine of the conservation 

 of energy ; namely, that the sum of energy, actual and potential, in 

 the world is always one and the same. Causes are not causes simply 

 because they are antecedents ; they are antecedent of the effects be- 

 cause they have power to produce them. 



It would be preposterous in so short a paper as this to dive into 

 all the sub'tilties of the subjective question as to whether our belief in 

 causation is intuitive, or is derived from a gathered experience. The 

 settlement of this question will depend on the way we settle the one 

 started under the last head, as to whether there are not truths which 

 shine in their own light. If there be such truths, then causation is un- 

 doubtedly one of them. When we see a thing produced, a new thing, 

 or a change in an old thing, we look for a producing cause having 

 power in its very nature, and ready to produce the same effect in the 

 same circumstances. 



7. By his doctrine, defective as I reckon it, Hume undermined the 

 argument for the Divine existence. There is evidence in his life, in 

 his correspondence, and in his philosophic writings, that, like John 

 Stuart Mill, in a later age, he looked with a feeling of favor upon the 

 seeming evidence for the existence of a designing Mind in the uni- 



