INTRODUCTION, 



THE Tracts contained in this small volume will, 

 I trust, be perused with considerable interest by 

 every English reader who is a lover of ancient 

 lore; and whatever innovations may have been 

 made in the philosophical theories of the ancients 

 by the accumulated experiments of the moderns, 

 yet the scientific deductions of the former will, I 

 am persuaded, ultimately predominate over the 

 futile and ever-varying conclusions of the latter. 

 For science, truly so called, is, as Aristotle accu- 

 rately defines it to be, the knowledge of things 

 eternal, and which have a necessary existence. 

 Hence it has for its basis universals, and not par- 

 ticulars ; since the former are definite, immutable, 

 and real / but the latter are indefinite, are so in- 

 cessantly changing, that they are not for a moment 

 the same, and are so destitute of reality, that, in 

 the language of the great Plotinus, they may be 

 b 



