ttribute is meant, according to the fourth definition,
"that which the understanding perceives of substance as constituting the
essence of it" _(quod intellectus de substantia percipit, tanquam ejusdem
essentiam constituens)_. The more reality a substance contains, the more
attributes it has; consequently infinite substance possesses an 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