All men endeavor after continuance of existence (III. prop. 6); why not all after virtue?  If all endeavor after it, why do so few reach the goal?  Whence the sadly large number of the irrational, the selfish, the vicious?  Whence the evil in the world?  Vice is as truly an outcome of “nature” as virtue.  Virtue is power, vice is weakness; the former is knowledge, the latter ignorance.  Whence the powerless natures?  Whence defective knowledge?  Whence imperfection in general?

The concept of imperfection expresses nothing positive, nothing actual, but merely a defect, an absence of reality.  It is nothing but an idea in us, a fiction which arises through the comparison of one thing with another possessing greater reality, or with an abstract generic concept, a pattern, which it seems unable to attain.  That concepts of value are not properties of things themselves, but denote only their pleasurable or painful effects on us, is evident from the fact that one and the same thing may be at the same time good, bad, and indifferent:  the music which is good for the melancholy man may be bad for the mourner, and neither good nor bad for the deaf.  Knowledge of the bad is an abstract, inadequate idea; in God there is no idea of evil.  If imperfection and error were something real, it would have to be conceded that God is the author of evil and sin.  In reality everything is that which it can be, hence without defect:  everything actual is, in itself considered, perfect.  Even the fool and the sinner cannot be otherwise than he is; he appears imperfect only when placed beside the wise and the virtuous.  Sin is thus only a lesser reality than virtue, evil a lesser good; good and bad, activity and passivity, power and weakness are merely distinctions in degree.  But why is not everything absolutely perfect?  Why are there lesser degrees of reality?  Two answers are given.  The first is found only between the lines:  the imperfections in the being and action of individual things are grounded in their finitude, particularly in their involution in the chain of causality, in virtue of which they are acted on from without, and are determined in their action not by their own nature only, but also by external causes.  Man sins because he is open to impressions from external things, and only superior natures are strong enough to preserve their rational self-determination in spite of this.  The other answer is expressly given at the end of the first part (with an appeal to the sixteenth proposition, that everything which the divine understanding conceives as creatable has actually come into existence).  “To those who ask why God did not so create all men that they should be governed only by reason, I reply only:  because matter was not lacking to him for the creation of every degree of perfection from highest to lowest; or, more strictly, because the laws of his nature were so ample as so suffice for the production of everything conceivable by an