56 NATlrilAL THEOLOai. 



glasses and tubes of a dioptric telescope are suited to thaV 

 purpose, it concerns not the proof which these afford of de- 

 sign, and of a designer, that there may perhaps be ether 

 parts, certain muscles, for instance, or nerves in the same 

 eyC; of the agency or effect of which we can give no ac- 

 count, any more than we should be inclined to doubt, oi 

 ought to doubt, about the construction of a telescope, name- 

 ly, for what purpose it was constructed, or whether it was 

 constructed at all, because there belonged to it certain screws 

 and pins, the use or action of which we did not comprehend. 

 I take it to be a general way of infusing doubts and scruples 

 into the mind, to recur to its own ignorance, its own imbe- 

 cility — to tell us that upon these subjects we know little ; 

 that little imperfectly ; or rather, that we knoAV nothing 

 properly about the matter. These suggestions so fall in 

 with our consciousness as sometimes to produce a general 

 distrust of our faculties and our conclusions. But this is an 

 unfounded jealousy. The uncertamty of one thmg does not 

 necessarily aflect the certainty of another thing. Our igno 

 ranee of many points need not suspend our assurance of a 

 few. Before we yield, in any particular instance, to the 

 scepticism which this sort of insinuation would induce, wo 

 ought accurately to ascertain whether our ignorance oi 

 doubt concern those precise points upon which our conclu- 

 sion rests. Other points are nothing. Our ignorance ol 

 other points may be of no consequence to these, though they 

 be points, in various respects, of great importance. A just 

 reasoner removes from his consideration not only what he 

 knows, but what he does not know, touching matters not 

 strictly connected with his argument, that is, not forming 

 the very steps of his deduction : beyond these, his knoA\ ledge 

 and his ignorance are alike relative. 



