infinite number, each of which gives expression to its essence, but of which two only fall within our knowledge.  Among the innumerable divine attributes the human mind knows those only which it finds in itself, thought and extension.  Although man beholds God only as thinking and extended substance, he yet has a clear and complete; an adequate—­idea of God.  Since each of the two attributes is conceived without the other, hence in itself (per se), they are distinct from each other realiter, and independent.  God is absolutely infinite, the attributes only in their kind (in suo genere).

How can the indeterminate possess properties?  Are the attributes merely ascribed to substance by the understanding, or do they possess reality apart from the knowing subject?  This question has given rise to much debate.  According to Hegel and Ed. Erdmann the attributes are something external to substance, something brought into it by the understanding, forms of knowledge present in the beholder alone; substance itself is neither extended nor cogitative, but merely appears to the understanding under these determinations, without which the latter would be unable to cognize it.  This “formalistic” interpretation, which, relying on a passage in a letter to De Vries (Epist. 27), explains the attributes as mere modes of intellectual apprehension, numbers Kuno Fischer among its opponents.  As the one party holds to the first half of the definition, the other places the emphasis on the second half ("that which the understanding perceives—­as constituting the essence of substance").  The attributes are more than mere modes of representation—­they are real properties, which substance possesses even apart from an observer, nay, in which it consists; in Spinoza, moreover, “must be conceived” is the equivalent of “to be.”  Although this latter “realistic” party undoubtedly has the advantage over the former, which reads into Spinoza a subjectivism foreign to his system, they ought not to forget that the difference in interpretation has for its basis a conflict among the motives which control Spinoza’s thinking.  The reference of the attributes to the understanding, given in the definition, is not without significance.  It sprang from the wish not to mar the indeterminateness of the absolute by the opposition of the attributes, while, on the other hand, an equally pressing need for the conservation of the immanence of substance forbade a bold transfer of the attributes to the observer.  The real opinion of Spinoza is neither so clear and free from contradictions, nor so one-sided, as that which his interpreters ascribe to him.  Fischer’s further interpretation of the attributes of God as his “powers” is tenable, so long as by causa and potentia we understand nothing more than the irresistible, but non-kinetic, force with which an original truth establishes or effects those which follow from it.