In brief: Because what „works“ depends on how the matter is constituted in which one acts. The maxim is no substitute for knowing the matter; it presupposes it. The Groundlines are the attempt to supply that knowledge for the social sphere – and expressly not a utopia.
The objection to short-winded pragmatism
A physician who pragmatically tries out preparations until one works is not a pragmatist but a quack. Whoever wants to act with a purpose must know the system into which he is intervening. For the social sphere that means: whoever does not know the basic determinations he works with – person, property, contract, imputation, institution – is hammering marble as though it were wood.
This is not an argument for theory against practice. It is the observation that there is no presuppositionless practice: whoever acts always already has a conception of what he is dealing with. The only question is whether it has been examined.
Why this book in particular
Because the Groundlines design no utopia. The Preface says expressly that the point is to comprehend what is – philosophy „always comes too late“ to instruct the world (see the owl of Minerva). What the book offers is an anatomy, not a vision.
Two passages show what this yields in practice.
The market. § 189–§ 208 describe the „system of needs“ as an order that regulates itself. But § 241–§ 245 show that in doing so it produces a problem it cannot solve: poverty and the emergence of the rabble. Hegel ends there not with a proposal but with a finding: that, „in the face of the excess of wealth“, civil society is „not wealthy enough“. Whoever takes poverty for an accident of operation to be remedied with alms does not have this systemic connection before him.
The state. § 257 ff. deny that a state is a contract that can be recast at will. § 273 note treats the question who should make a constitution as senselessly put, and § 258 note warns against the attempt to begin „entirely afresh, from thought alone“. Whoever designs an efficient constitution at the drawing board and is surprised that it is not accepted will find the diagnosis here.
What the book does not do
It makes nobody a better craftsman. Hegel himself holds it impossible to derive a code of laws from the philosophical development – philosophical right relates to positive right „rather as Institutes to Pandects“ (§ 3 note). And § 214 concedes that the last, practically decisive step of every application of law can no longer be rationally determined.
The yield is more modest and more durable: the insight into where a problem is structural and not a matter of craft. That spares nobody a decision, but it spares a few failed attempts.
Sources. Groundlines, Preface (the owl of Minerva), § 3 note, § 189–§ 208 (the system of needs), § 241–§ 245 (poverty and the rabble), § 214 note, § 257 ff., § 258 note, § 273 note. – On the American pragmatist tradition and its relation to Hegel see John Dewey, who in his autobiographical essay „From Absolutism to Experimentalism“ (1930) expressly acknowledges Hegel’s formative influence. – In the glossary: Civil Society, Poverty, Ethical Life.