D'ALEMBERT. 491 



find that these two operations are performed by the same 

 means, the weight of the atmosphere, and that a sea-horse 

 climbs the ice-hills by no other power. Can anything be 

 more strange to contemplate ? Is there in all the fairy-tales 

 that ever were fancied anything more calculated to arrest the 

 attention, and to occupy and gratify the mind, than this most 

 unexpected resemblance between things so unlike, to the 

 eyes of ordinary beholders ? What more pleasing occupation 

 than to see uncovered and bared before our eyes the very 

 instrument and the process by which Nature works ? Then 

 we raise our views to the structure of the heavens ; and are 

 again gratified with tracing accurate but most unexpected 

 resemblances. Is it not in the highest degree interesting to 

 find, that the power which keeps this earth in its shape, and 

 in its path, wheeling upon its axis and round the sun, extends 

 over all the other worlds that compose the universe, and gives 

 to each its proper place and motion ; that this same power 

 keeps the moon in her path round our earth, and our earth 

 in its path round the sun, and each planet in its path ; that 

 the same power causes the tides upon our globe, and the pecu- 

 liar form of the globe itself ; and that, after all, it is the same 

 power which makes a stone fall to the ground \ To learn these 

 things, and to reflect upon them, occupies the faculties, fills 

 the mind, and produces certain as well as pure gratification. 

 But if the knowledge of the doctrines unfolded by science 

 is pleasing, so is the being able to trace the steps by which 

 those doctrines are investigated, and their truth demonstrated: 

 indeed, you cannot be said, in any sense of the word, to have 

 learnt them, or to know them, if you have not so studied them 

 as to perceive how they are proved. Without this, you never 

 can expect to remember them long, or to understand them 

 accurately; and that would of itself be reason enough for 

 examining closely the grounds they rest on. But there is the 

 highest gratification of all, in being able to see distinctly those 

 grounds, so as to be satisfied that a belief in the doctrines is 

 well founded. Hence to follow a demonstration of a grand 

 mathematical truth to perceive how clearly and how inevit- 

 ably one step succeeds another, and how the whole steps lead 

 to the conclusion to observe how certainly and unerringly 

 the reasoning goes on from things perfectly self-evident, and 



