144 



SCIENTIFIC THOUGHT. 



so easily handled. The correct use of scientific ideas is 

 only learned by patient training, and should be governed 

 by the not easily acquired habit of self-restraint. It is 

 well known how the fundamental notions of a mechanical 

 science, let loose into literature by Fontenelle, by D'Alem- 

 bert, by Condorcet, or absorbed by Voltaire and Diderot, 

 were expanded into a system of materialistic philosophy 

 in ' L'Homme Machine/ the ' Systeme de la Nature,' and 

 other works, the extreme views of which the great scien- 

 tific thinkers could hardly approve of. 1 These hasty but 



1 As a great deal of confusion ex- 

 isted for a long time in European 

 literature as to the exact succession 

 in time of the different works which 

 assisted to spread mechanical views 

 of the world and of life, I put down 

 the main dates : 



Fontenelle (1657-1757) published 

 his Eloges of the great Academi- 

 cians, in which the principles of 

 the philosophy of Descartes, Leib- 

 niz, and Newton were popularly 

 expounded and discussed, from 

 1700 onward. His 'Pluralite des 

 Mondes' had appeared already in 

 1686 ; it had 'popularised Cartesian 

 ideas. 



Voltaire (1694-1778) published 

 his ' Ele'mens de la Philosophie de 

 Newton' in 1738. 



La Mettrie (1709-51) published 

 his ' Histoire uaturelle de 1'Ame ' 

 in 1745, and his ' L'Homme 

 Machine' in 1748. 



D'Alembert and Diderot pub- 

 lished the first volume of the ' En- 

 cyclopedic ' in 1751. 



Buffon (1707-88) published, 1749, 

 his ' The"orie de la Terre,' being the 

 first portion of the ' Histoire natur- 

 elle.' 



Holbach (1723-89) published 

 under the name of Mirabaud, 

 1770, the 'Systeme de la Nature.' 



Of these works, the three which 



created the greatest popular sensa- 

 tion viz., Voltaire's ' Elemens,' 

 La Mettrie's ' L'Homme Machine,' 

 and Holbach's ' Systeme ' were all 

 published in Holland. Voltaire, 

 D'Alembert, and Diderot appear to 

 have approached philosophical prob- 

 lems mainly from the position of 

 Newton's natural philosophy, La 

 Mettrie from the teachings of the 

 great Boerhaave, Holbach princi- 

 pally from a study of chemistry. 

 It is unnecessary to say that none 

 of them had the sanction of their 

 great masters for the applications 

 they made of principles which had 

 been established and used for special 

 scientific purposes. And the same 

 may be said with reference to the 

 influence of Locke, which in almost 

 all the instances mentioned was- 

 combined with that of the great 

 naturalists. But this does not be- 

 long to the line of thought in which 

 we are interested at present. For 

 the sake of completeness only I 

 mention that Locke's teachings as 

 well as Newton's were made popu- 

 larly known in France by Voltaire's 

 " Lettres sur les Anglais' (burnt by 

 order of the Parliament of Paris in 

 1734), whereas Condillac's (1714-80) 

 more systematic treatise, entitled 

 ' Essai sur I'Origine des Connaissances 

 humaines,' appeared in 1746. It is- 



