LIFE of Dr HUTTON. 81 



conclufions of the antiphlogiftic theory have been drawn with 

 too much precipitancy, and carried farther than is warranted by 

 the ftfict rules of inductive philofophy. 



The fubjecl of Fire, Light and Heat was refumed by Dr 

 Hutton feveral years after this period, and formed the fubje<5l 

 of a feries of papers which he read in the Royal Society of Edin- 

 burgh, and afterwards publiihed feparately. He there explains 

 more fully his notion of the fubftances juft mentioned, which 

 he confiders as different modifications of the folar matter, alike 

 deftitute of inertnefs and of gravity. 



A more voluminous work from Dr Hutton's pen, made its 

 appearance foon after the Phyfical DifTertations, viz. An Invejlu 

 gat ion of the Principles of Knowledge, and of the Progrefs of Rea- 

 fon from Senfe to Science and Philofophy, in three volumes quarto. 



He informs us himfelf of the train of thought by which he 

 was led to the metaphyfical fpeculations contained in thefe vo- 

 lumes. He had fatisfied himfelf, by his phyfical inveftigations, 

 that body is not what it is conceived by us to be, a thing necef- 

 farily pofTeffing volume, figure and impenetrability, but merely 

 an affemblage of powers, that by their action produce in us the 

 ideas of thefe external qualities. His curiofity, therefore, was 

 naturally excited to inquire farther into the manner in which 

 we form our conceptions of body, or into the nature of the in- 

 tercourfe which the mind holds with thofe things that exift 

 without it. In purfuing this inquiry, he foon became convin- 

 ced, that magnitude, figure and impenetrability, are no otherwife 

 perceived by the mind than colour, tafte and fmell ; that is, that 

 what are called the primary qualities of body, are precifely on 

 the fame footing with the fecondary, and are both conceptions 

 of the mind, which can have no refemblance to the external 

 caufe by which thofe conceptions are produced. The world, 

 therefore, as conceived by us, is the creation of the mind itfelf, 

 but of the mind a&ed on from without, and receiving informa- 



L 2 tion 



