All adherents of the Eleatic separation of the one pure being from the manifold and changing world of appearance are compelled to make a like distinction between two kinds and two organs of knowledge.  The representation of the empirical manifold of separately existing individual things, together with the organ thereof, Spinoza terms imaginatio; the faculty of cognizing the true reality, the one, all-embracing substance, he calls intellectus.  Imaginatio (imagination, sensuous representation) is the faculty of inadequate, confused ideas, among which are included abstract conceptions, as well as sensations and memory-images.  The objects of perception are the affections of our body; and our perceptions, therefore, are not clear and distinct, because we are not completely acquainted with their causes.  In the merely perceptual stage, the mind gains only a confused and mutilated idea of external objects, of the body, and of itself; it is unable to separate that in the perception (e.g., heat) which is due to the external body from that which is due to its own body.  An inadequate idea, however, is not in itself an error; it becomes such only when, unconscious of its defectiveness, we take it for complete and true.  Prominent examples of erroneous ideas are furnished by general concepts, by the idea of ends, and the idea of the freedom of the will.  The more general and abstract an idea, the more inadequate and indistinct it becomes; and this shows the lack of value in generic concepts, which are formed by the omission of differences.  All cognition which is carried on by universals and their symbols, words, yields opinion and imagination merely instead of truth.  Quite as valueless and harmful is the idea of ends, with its accompaniments.  We think that nature has typical forms hovering before it, which it is seeking to actualize in things; when this intention is apparently fulfilled we speak of things as perfect and beautiful; when it fails, of imperfect and ugly things.  Such concepts of value belong in the sphere of fictions.  The same is true of the idea of the freedom of the will, which depends on our ignorance of that which constrains us.  Apart from the consideration that “the will,” the general conception of which comes under the rubric of unreal abstractions, is in fact merely the sum of the particular volitions, the illusion of freedom, e.g., that we will and act without a cause, arises from the fact that we are conscious of our action (and also of its proximate motives), but not of its (remoter) determining causes.  Thus the thirsty child believes it desires its milk of its own free will, and the timid one, that it freely chooses to run away (Ethica, III. prop. 2, schol.; I. app.) If the falling stone were conscious, it would, likewise, consider itself free, and its fall the result of an undetermined decision.