462 ON THE SUCCESSIVE FORMS 



observation and reasoning, they can seek in the works 

 of the Cosmogonists. Where \ve have neither expe- 

 rience nor analogy for our guides, all is conjecture and 

 darkness. As far as these extend, we are within the 

 hounds of philosophical inquiry : beyond it, lies the 

 free space, the ethereal region of poetry. 



I must nevertheless allude, at least, to the specula- 

 tions of La Place, resting on far other grounds than 

 those of the Cosmogonists in question ; though I 

 presume that they are too well known to require 

 detail. They are rational and philosophical, should 

 they not be proved true ; but I do not fed "that I am 

 even justified in stating the appearances and analogies 

 on which they rest, in a place where I have undertaken 

 to detail only what can be deduced from observation 

 and reasoning upon the earth as we know it. Here- 

 after, this fundamental Theory of the Earth may find 

 a fitter place. 



It is the object, therefore, of the following discus- 

 sion, to trace the disposition of the rocky surface of 

 the globe, from that most distant or early point at 

 which the marks of change are perceptible, and to pursue 

 its changes down to the present day, from the time at 

 which these marks of revolution disappear. Beyond 

 that distant point, it is possible that there may have 

 been other changes; but, of these, we can find no 

 Evidence. A curtain is here drawn, to separate the 

 visible world from that which is, to us, as if it had 

 never existed. That this System had a beginning, we 

 are certain : where that may lie, we know not ; but, 

 for us, it is placed beyond that aera at which we can 

 no longer trace the marks of a change of order, of the 

 destruction and renovation of its form. It is from this 

 point that a Theory of the Earth must at present 

 commence : it is from this also that the present inquiry 



