300 NEW SYSTEM 



and I rightly contemned the method of those who make 

 use only of forms and faculties, from which we learn 

 nothing 9 . But afterwards, having tried to go deeply 

 into mechanical principles themselves, in order to find 

 a reason for the laws of nature which experience makes 

 known, I perceived that the mere consideration of an 

 extended mass is not sufficient and that use must also be 

 made of the notion of force, which is very intelligible, 

 though it belongs to the sphere of metaphysics 10 . It 

 appeared to me also that the view of those who trans- 

 form or degrade the lower animals into mere machines, 

 although it seems possible, is improbable and indeed is 

 contrary to the order of things. 



3. At first, when I had freed myself from the yoke 

 of Aristotle, I took to the void and the atoms, for that 

 is the view which best satisfies the imagination. But 

 having got over this, I perceived, after much medita- 

 tion, that it is impossible to find the principles of a real 

 unity in matter alone, or in that which is only passive, 

 since it is nothing but a collection or aggregation of parts 

 ad infinitum". Now a multiplicity [multitude] can derive 

 its reality only from genuine units [unites] which come 

 from elsewhere and are quite other than the mathematical 

 points which are only extremities of the extended and 



9 See Introduction, Part i. p. 3, and Part iv. p. 156. 



10 The meaning is that, although force is not anything that 

 can be pictured or represented in imagination, it can nevertheless 

 be quite well understood. The notion of force is ' metaphysical, ' 

 because force is not merely a physical thing that can be perceived 

 in the same way as other physical things. For instance, we 

 can understand, but we cannot perceive, the potential energy 

 of a mass. In the First Draft, Leibniz says : ' By force or power 

 [jpuissance] I do not mean the power [powroi'r] or mere faculty, 

 which is nothing but a near possibility of acting and which, being 

 as it were dead, never produces an action without being stimulated 

 from without, but I mean something between power to act [pouwir] 

 and action, something which includes an effort, an actual working 

 [acfe], an entelechy, for force passes of itself into action, in so far 

 as nothing hinders it. Wherefore I regard force as constitutive 

 of substance, since it is the source [principe~] of action, which is 

 the characteristic of substance ' (G. iv. 472). 



11 Cf. Introduction, Part ii. p. 23. 



