NOTES AND REFERENCES 

 TO THE CORRELATION OF PHYSICAL FORCES. 



5. THE reader who is curious as to the views of the ancients 



regarding the objects of science, will find clues to them in the 

 second book of ARISTOTLE'S Physics, and in the first three 

 books of the Metaphysics. See also the Timseus of PLATO, 

 and RITTER'S History of Ancient Philosophy, where a sketch 

 of the Philosophy of LEUCIPPUS and DEMOCRITUS will be 

 found. 



6. BACON'S Novum Organum, book ii. aph. 5 and 6. 



7. HUME'S Enquiry concerning Human Understanding, S. 7, 



London, 1768. 



BROWN'S Enquiry into the Relations of Cause and Effect, Lon- 

 don, 1835. 



The illustration I have used of a floodgate has been objected 

 to, as being one to which the term cause would scarcely be 

 applied, but after some consideration I have retained it j if 

 cause be viewed only as sequence, it must be limited to 

 sequence under given conditions or circumstances, and here, 

 given the conditions, the sequence is invariable. I see no 

 difference quoad the argument, between this illustration and 

 that of BROWN of a lighted match and gunpowder (4th edit, 

 p. 27), to which my reasoning would equally well apply. 



HERSCHEL'S Discourse on the Study of Natural Philosophy, 

 pp. 88 and 149. 



8. Quarterly Review, vol. Ixviii, p. 212. 



WHEWELL, On the Question * Are Cause and Effect Successive 

 or Simultaneous ? ' (Cambridge Philosophical Transactions, 

 vol. vii. p. 319). 



