58 PHILOSOPHICAL THOUGHT. 



become evident that in relation to those several distinct 

 aspects which I have defined, all the important doctrines 

 of philosophy and many underlying and hidden currents of 

 thought will come under review. Frequently, also, lines 

 of reasoning otherwise far apart and apparently diverg- 

 ent will be shown to reveal the same or similar ten- 

 dencies. Thus the logical and metaphysical development 

 of thought will not only deal with the .philosophies of 

 Kant and his immediate successors, but also with that 

 independent development which centres in John Stuart 

 Mill. Psychology will not only embrace the Scottish 

 school of philosophy, but also that of Herbart, Fechner, 

 and Wundt in Germany, as well as the more recent 

 contributions of the French school; positivism will for 

 us mean not only the philosophy of Comte, but also 

 many cognate developments in England, though they 

 refuse allegiance to Comte,; as also the latest theory of 

 scientific knowledge which we connect with the name 

 of Professor Ernst Mach. The great idea of develop- 

 ment will, as has been stated above, have two sides, of 

 which, far distant as they otherwise appear, Hegel and 

 Herbert Spencer are nevertheless together the main 

 representatives. Almost all the leading thinkers of this 

 century have, to a greater or less extent, attacked the 

 problem of monism or dualism, which historically can be 

 traced back to Leibniz, whose ideas in one form or 

 another 'meet us again in the speculations of very oppo- 

 site schools of recent philosophy. We cannot understand 

 the position which philosophy has taken up towards the 

 religious question without recalling the influence of 

 Jacobi and Schleiermacher abroad, or of Hamilton and 



