GENERAL PRINCIPLES 45 



that it is an hypothesis which seeks to reconcile the 

 contrary views of Scholastics and Cartesians l . 



The scholastic theory of an in/luxus physi cus connected 

 soul and body in a way which ultimately confounded 

 them, making it impossible to draw any clear line 

 between them. The Cartesian or Occasionalist view, on 

 the other hand, separated them so absolutely that nothing 

 but a purely arbitrary connexion could be supposed a 

 connexion external to the nature of both. The Scholastics 

 seemed to Leibniz to be right in holding that the con- 

 nexion is a real one, grounded in the nature of the 

 substances ; the Cartesians seemed right in maintaining 

 that the substances are mutually exclusive. And the 

 antinomy is solved for Leibniz by the supposition of a 

 mutual 'ideal influence/ a relationship of perception or 

 representation, between independent self-active Monads, 

 the harmony of whose inner developments has been 

 established before their creation 2 . 



Leibniz's Illustrations of the pre-established Harmony 

 the Clocks and the Choirs. 



The simile of the clocks, by means of which Leibniz 

 illustrates his theory in relation to the Scholastic and 

 Cartesian views, is given in the Tliird Explanation of his 

 New System. Two clocks may be made to keep perfect 

 time with one another in three different ways. They 

 may be actually connected together, for instance by 

 a piece of wood, in such a way that there is a mutual 

 transference of vibrations between them, resulting in a 

 perfect agreement of the motions of the pendulums 3 . Or, 



1 Of. H. C. W. Sigwart, Die Leibnizsche Lehre von *der prastablirten 

 Harmonic in ihrem Zusammenhange mit fruheren Philosophemen betrachtet 

 (Tubingen, 1822), pp. 107 sqq. 



2 For an application of the doctrine of pre-established harmony 

 to a particular case, see Appendix A, p. 200. 



3 This was suggested to Leibniz by an experiment of Huygens, 

 who hung two pendulums on a bar of wood, and found that, though 

 they were set swinging out of time with one another, the vibra- 

 tions which each gave to the bar of wood caused them ultimately 

 to swing in harmony. Cf. Third Explanation of the New System, p. 332. 



