8 



Kant considers that Space and Time are conditions of 

 perception, and hence, sources of necessary and universal 

 truth. Dr Whewell agrees with Kant in placing in the mind 

 certain sources of necessary truth ; he calls these Funda- 

 mental Ideas, and reckons, besides Space and Time, others, 

 as Cause, Likeness, Substance, and several more. Mr Mill, 

 the most recent and able expounder of the opposite doctrine, 

 derives all truths from Observation, and denies that there 

 is such a separate source of truth as Ideas. Mr Mansel 

 does not agree either with Mr Mill or Dr Whewell ; he ad- 

 heres to the original Kantian thesis, that Space and Time are 

 sources of necessary truths, but denies the office to the other 

 Fundamental Ideas of Dr Whewell. In reading what has 

 been said by Mr Mill, Mr Mansel, and other critics, on the 

 subject of what I have called Fundamental Ideas, I am led 

 to perceive that I have expressed myself incautiously, with 

 regard to the identity of character between the first two of 

 these Fundamental Ideas, namely, Space and Time, and the 

 others, as Force, Composition, and the like. And I am 

 desirous of explaining, to those who take an interest in these 

 speculations, how far I claim for the other Fundamental 

 Ideas the same character and attributes as for Space and 

 Time. 



The special and characteristic property of all the Funda- 

 mental Ideas is what I have already mentioned, that they 

 are the mental sources of necessary and universal scientific 

 truths. I call them Ideas, as being something not derived 

 from sensation, but governing sensation, and consequently, 

 giving form to our experience ; Fundamental, as being the 

 foundation of knowledge, or at least of Science. And the way 

 in which those Ideas become the foundations of Science is, that 

 when they are clearly and distinctly entertained in the mind, 

 they give rise to inevitable convictions or intuitions, which 

 may be expressed as Axioms; and these Axioms are the 

 foundations of Sciences respective of each Idea. The Idea of 



