Main idea

The rule of the single centre of gravity — everything a note contains serves the same idea — applies to the building block, not to the assembly. A page that puts several notes in relation necessarily carries several ideas: those of the notes it links. Applying the building block's rule to it would amount to forbidding it to exist.

What replaces the rule is not its abandonment. The unity moves: from the idea to the angle. Several propositions legitimately live together if each contributes to the same reading; a proposition that contributes nothing to that reading has no place there, even if it deals with the same subject.

The difference between the two objects is therefore functional, not quantitative. A building block stabilises an idea so that you can lean on it; an assembly organises a small set of blocks so that you can see what they draw.

Why it matters

This defuses a false charge. An assembly page is often reproached for "talking about several things", which is its function; the real reproach, when it is founded, is that it talks about several things that do not serve the same reading.

It also gives the right sorting question when the page grows: not "how many ideas are there here?", but "which of these ideas does not serve the angle?".

Nuances and limits

The angle can be phrased vaguely enough to admit everything. "Knowledge in the enterprise" passes itself off as an angle and works as a subject: the unity it guarantees is nil, and the rule stops biting.

And an assembly carrying ten ideas would no longer be readable, even with a sharp angle: the absence of a quantitative limit only holds within a small constellation.

Open questions

• Is there a way to test an angle before assembling, other than noticing afterwards that it excluded nothing?