Philosophy of the Human Mind. 25 



their combination with our perceptions; but it is 

 only in connection with our perceptions that these 

 pure notions can be the source of knowledge; for, 

 in themselves, they are mere forms, without any 

 independent existence. They serve to direct us in 

 the use of our observations ; but they cannot extend 

 our knowledge beyond the limits of perception 

 and experience. " 



" There are, according to Professor Kant, two 

 kinds of propositions, concerning which our minds 

 may be employed, analytical and synthetical. 

 The former are those in which we only explain or 

 illustrate that of which we have already some idea; 

 whereas, in the latter, we increase our knowledge, 

 by adding something new to our former idea of 

 the subject. Thus, when we say all matter is ex- 

 tended, we form an analytical proposition; and 

 when we say, all bodies have a certain zceight, that 

 is a synthetical proposition. 



" Without experience, we cannot form any syn- 

 thetical proposition concerning the objects or 

 matter of our knowledge ; but, as the forms of our 

 knowledge are independent of and prior to our ex- 

 perience, we may, with respect to the pure notions 

 already mentioned, conceive synthetical proposi- 

 tions, or acquire pure science; and indeed it is 

 only when we have pure perceptions and pure no- 

 tions for our objects, that we can arrive at univer- 

 sal and necessary certainty; as is the case in pure 

 mathematics and philosophy, in which we con- 

 sider truth, abstracted from matter, with respect 

 only to the forms or laws of knowledge and volition, 

 " Beside theoretical reason, M. Kant ascribes 

 to man another faculty, which he calls practical 

 reason, endued with power sufficient to impel and 

 direct the will. He asserts that, if this faculty 

 were not granted, it w^ould follow that practical 

 laws would not be universal moral precepts^ but 

 vol. ji. E 



