If the corporeal world is more than representation we must say it is will, because nothing but will and representation is known or thinkable to us

The passage

Because any reality attributed to the corporeal world beyond its being representation must be one known or thinkable to us, and besides will and representation nothing is known or thinkable to us, if the corporeal world is to be more than our representation we must say that it is in itself will.

The argument

1. P1Assumption. If the corporeal world is to be something more than merely our representation, the reality attributed to it beyond representation must be a reality known or thinkable to us (the map's bridge, from the two questions at ZA I 148: what other kind of existence or reality should we attribute to it, whence take the elements to compose one)
2. P2Besides the will and the representation nothing at all is known to us, nor thinkable
3. P3Assumption. A reality attributed to the corporeal world beyond its being representation is not representation (what »mehr als bloß unsere Vorstellung« means, ZA I 148)
4. Infer.hypothetical syllogism with elimination of a disjunct
5. CIf the corporeal world is more than our representation, we must say it is in itself what we find in ourselves as will

The argument is the run of sentences in § 19 (ZA I 148) from »Denn welche andere Art von Daseyn oder Realität sollten wir der übrigen Körperwelt beilegen?« to »so müssen wir sagen, daß sie außer der Vorstellung, also an sich und ihrem Innersten Wesen nach, Das sei, was wir in uns selbst unmittelbar als Willen finden« (the section continues for five more sentences, on what belongs to the will's essence and what to its appearance). The »Denn« gives the reason for the assumption stated just before it, that what remains of other objects when their existence as representation is set aside must be will (c-schopenhauer-other-objects-judged-by-analogy-with-body), and the »Wenn also« sentence restates that assumption as a conditional, which is the conclusion claim. Schopenhauer introduces the whole step as a judgment »nach Analogie jenes Leibes« and an assumption (»annehmen«, ZA I 147–148), and the paragraph before says that theoretical egoism, which denies that objects known only as representations are appearances of a will, »ist zwar durch Beweise nimmermehr zu widerlegen« (ZA I 147). The argument therefore gives a reason, not a proof; its conclusion is conditional and epistemic, what we »müssen sagen«, and it does not claim to establish its antecedent.

What the form captures and what it leaves out. Premise 1 is the map's: the text asks two rhetorical questions, what other reality we should attribute and whence we should take the elements, and the premise states the principle they presuppose, that a reality we can attribute must be one we know or can think. Premise 2 is the text's answer, »Außer dem Willen und der Vorstellung ist uns gar nichts bekannt, noch denkbar«: a reality known or thinkable to us is representation or will. Premise 3 is the map's, and only says that a reality beyond representation is not representation; the form needs it to eliminate the disjunct. The text's own chain between premise 2 and the conclusion is not formalized: that the greatest reality we can attribute to the corporeal world is the one our own body has, »denn der ist Jedem das Realste«; that the body's reality, apart from representation, is nothing but will (c-schopenhauer-reality-of-body-exhausted-by-will); and »daher« that no other reality can be found to attribute. The form says nothing about whether premise 1 is true.