determine the mind to an idea, nor the soul the body to a movement.  Since, however, extension and thought are not two substances, but attributes of one substance, this apparently double causal nexus of two series proceeding in exact correspondence is, in reality, but a single one. (III. prop. 2, schol.) viewed from different sides.  That which represents a chain of motions when seen from the side of extension, bears the aspect of a series of ideas from the side of thought. Modus extensionis et idea illius modi una cademque est res, sed duobus modis expressa (II. prop. 7, schol.; cf.  III. prop. 2, schol.).  The soul is nothing but the idea of an actual body, body or motion nothing but the object or event in the sphere of extended actuality corresponding to an idea.  No idea exists without something corporeal corresponding to it, no body, without at the same time existing as idea, or being conceived; in other words, everything is both body and spirit, all things are animated (II. prop. 13, schol.).  Thus the famous proposition results; Ordo et connexio idearum idem est ac ordo et connexio rerum (sive corporum; II. prop. 7), and in application to man, “the order of the actions and passions of our body is simultaneous in nature with the order of the actions and passions of the mind” (III. prop. 2, schol.).

The attempt to solve the problem of the relation between the material and the mental worlds by asserting their thoroughgoing correspondence and substantial identity, was philosophically justifiable and important, though many evident objections obtrude themselves upon us.  The required assumption, that there is a mental event corresponding to every bodily one, and vice versa, meets with involuntary and easily supported opposition, which Spinoza did nothing to remove.  Similarly he omitted to explain how body is related to motion, mind to ideas, and both to actuality.  The ascription of a materialistic tendency to Spinoza is not without foundation.  Corporeality and reality appear well-nigh identical for him,—­the expressions corpora and res are used synonymously,—­so that there remains for minds and ideas only an existence as reflections of the real in the sphere of [an] ideality (whose degree of actuality it is difficult to determine).  Moreover, individualistic impulses have been pointed out, which, in part, conflict with the monism which he consciously follows, and, in part, subserve its interests.  An example of this is given in the relation of mind and idea:  Spinoza treats the soul as a sum of ideas, as consisting in them.  An (at least apparently substantial) bond among ideas, an ego, which possesses them, does not exist for him:  the Cartesian cogito has become an impersonal cogitatur or a Deus cogitat.  In order to the unique substantiality of the infinite, the substantiality of individual spirits must disappear.  That which argues for the latter is their I-ness (Ichheit), the unity of self-consciousness; it is destroyed, if the mind is a congeries of ideas, a composite of them.  Thus in order to relieve itself from the self-dependence of the individual mind, monism allies itself with a spiritual atomism, the most extreme which can be conceived.  The mind is resolved into a mass of individual ideas.