Partizip 1 vs Partizip 2 im Partizipialattribut

Question

I think that the sentence

Das Töten von Tauben ist allerdings eine Maßnahme, die nicht zu gestatten ist

can be reformulated with an extended participle as

Das Töten von Tauben ist allerdings eine nicht zu gestattete Maßnahme.

However my grammar books says the correct answer is

Das Töten von Tauben ist allerdings eine nicht zu gestattende Maßnahme.

I cannot understand why the active version would be used. To my mind the form 'gestattete' should be correct, because Maßnahme is not an agent. Where am I wrong?

Answer 1

Using Partizip II would be correct if zu is omitted:

Das Töten von Tauben ist allerdings eine nicht gestattete Maßnahme.

The Partizip II cannot be used with zu in this kind of sentence. This combination with zu only works with the infinitive and the Partizip I. This combination is used predicatively with the infinitive and attributively with Partizip I. The combination of zu and Partizip I is sometimes called gerundive (Gerundivum in German), following languages like Latin where a distinct verbal form with this name exists.

Despite Partizip I having active meaning if used on its own, the combination with zu has passive meaning. It expresses necessity or - in the case of negation - impossibility. Becauseof this, Das Töten von Tauben ist allerdings eine nicht zu gestattende Maßnahme is correct.

Answer 2

Looking at the relative clause

1) (eine Maßnahme) die nicht zu gestatten ist

die (referring to Maßnahme) is the subject, just as in:

2) (eine Maßnahme) die nicht gestattet wurde

Both relative clauses are passive in the sense that the subject corresponds to the logical object of gestatten, i.e. the thing being permitted.

Used attributively, these become

1') die nicht zu gestattende Maßnahme
2') die nicht gestattete Maßnahme

with the noun corresponding to the subject of the relative clause (and again, the logical object of gestatten). The active variants, with the subject of the relative clause and the noun in the attributive construction corresponding to the logical subject of gestatten, are:

3) (eine Behörde) die etwas gestattet
3') die gestattende Behörde

Looking at 1')–3'), it is evident that German has three types of attributive infinitives: the zu-participle or gerundive zu gestattend, the past participle gestattet and the present participle gestattend‚ with the former two being passive. A combination of zu with the past participle (*zu gestattet) does not exist.

Regarding the terminology, see Kirsi Pakkanen-Kilpiä, "Zum Wesen des deutsches Gerundivs – Eine Korpuslinguistische Analyse", https://jyx.jyu.fi/bitstream/handle/123456789/37868/GERUNDIV%20final%20draft.pdf.

Answer 3

can be reformulated with an extended participle

This is neither the Partizip I or Partizip II but the so called Gerundivum, or participium necessitatis. It's the third participle German has, and it's always built from the Partizip I. Never from the Partizip II.

So the answer is simple:

… eine Maßnahme, die nicht zu gestatten ist. ← zu-Infinitiv

may be rephrased as

… eine nicht zu gestattende Maßnahme. ← Gerundivum

Just as your book says. This isn't a matter of active or passive because the Gerundivum is always built from the Partizip I.