OBSERVATION AND DESCRIPTION. 207 



thing else. It is inherent in a description, to be the 

 statement of a resemblance, or resemblances. 



These resemblances are not always apprehended 

 directly, by merely comparing the object observed with 

 some other present object, or with our recollection of 

 an object which is absent. They are often ascertained 

 through intermediate marks, that is, deductively. In 

 describing some new kind of animal, suppose me to 

 say that it measures ten feet in length, from the fore- 

 head to the extremity of the tail. I did not ascer- 

 tain this by the unassisted eye. I had a two-foot rule 

 which I applied to the object, and, as we commonly 

 say, measured it ; an operation which was not wholly 

 manual, but partly also mathematical, involving the 

 two propositions, Five times two is ten, and Things 

 which are equal to the same thing are equal to one 

 another. Hence, the fact that the animal is ten feet 

 long is not an immediate perception, but a conclusion 

 from reasoning ; the minor premisses alone being fur- 

 nished by observation of the object. But this does 

 not hinder it from being rightly called a description 

 of the animal. 



To pass at once from a very simple to a very 

 complex example : I affirm that the earth is globular. 

 The assertion is not grounded upon direct perception ; 

 for the figure of the earth cannot, by us, be directly 

 perceived, although the assertion would not be true 

 unless circumstances could be supposed under which 

 its truth could be so perceived. That the form of the 

 earth is globular, is inferred from certain marks, as 

 for instance from this, that its shadow thrown upon 

 the moon is circular; or this, that on the sea, or any 

 extensive plain, our horizon is always a circle ; either 

 of which marks is incompatible with any other than a 

 globular form. I assert further, that the earth is that 



