Page:An Enquiry Concerning Human Understanding - Hume (1748).djvu/114

 ment necessary for us to treat of in all our Disquisitions. We shall, therefore, endeavour, in this Essay, to fix, if possible, the precise Meaning of these Terms, and thereby remove some Part of that Obscurity, which is so much complain'd of in this Species of Philosophy.

seems a Proposition, which will not admit of much Dispute, that all our Ideas are nothing but Copies of our Impressions, or in other Words, that 'tis impossible for us to think of any Thing, which we have not antecedently felt, either by our external or internal Senses. I have endeavour'd in a former Essay to explain and prove this Proposition, and have express'd my Hopes, that, by a proper Application of it, Men may be able to reach a greater Clearness and Precision in philosophical Reasonings, than what they have hitherto been ever able to attain. Complex Ideas may, perhaps, be well known by Definition, which is nothing but an Enumeration of those Parts or simple Ideas, that compose them. But when we have push'd up Definitions to the most simple Ideas, and find still some Ambiguity and Obscurity; what Resource are we then possess'd of? By what Invention can we throw Light upon these Ideas, and render them altogether precise and determinate to our intel-