i.l INTRODUCTION. 23 



but I will not undertake to prove the assertion in this 

 work. The relations of time and space are logical 

 relations of a complicated character demanding much 

 abstract and difficult investigation. The subject has been 

 treated with such great ability by Peirce, 1 De Morgan, 2 

 Ellis, 3 and Harley, that I will not in the present work 

 attempt any review of their writings, but merely refer 

 the reader to the publications in which they are to be 

 found. 



1 Description of a Notation for the Logic of Relatives, resulting 

 from an Amplification of the Conceptions of Boole's Calculus of Logic. 

 By C. S. Peirce. Memoirs of the American Academy, vol. ix. Cam- 

 bridge, U.S., 1870. 



2 On the Syllogism No IV., and on the Logic of Relations. By 

 Augustus De Morgan. Transactions of the Cambridge Philosophical 

 Society, vol. x. part ii., 1860. 



3 Observations on Boole's Laws of Thought. By the late K. Leslie 

 Ellis ; communicated by the Rev. Robert Harley, F.R.S. Report of 

 the British Association, 1870. Report of Sections, p. 12. Also, On 

 Boole's Laws of Thought. By the Rev. Robert Harley, F.R.S., ibid. 

 p. 14. 



