Tom Sheehan on Ereignis from Eignung, Part I.

1. Heidegger interprets δύναμις as a moving thing’s Eignung (GA 9: 215.25; GA 19: 265.14; etc.), its condition of

• coming-into-its-own/eigen, coming-ad-proprium, that is:
• being ap-propri-ated by and unto its τέλος.

2. Two examples, one from nature (ϕύσις), the other from human know-how (τέχνη): 2.1 Nature (ϕύσις): An acorn has the δύναμις/Eignung of being an oak tree.

It is “drawn” into its proper wholeness by its τέλος (“oak tree”). This τέλος lies within the acorn; it is the origin and ordering (ἀρχή) of its movement.
Put otherwise, the acorn already has itself in its τέλος (ἐν τέλει ἔχει), but not fully.
The realness (actuality) of the acorn has the form of ἐν-τελ-έχεια ἀ- τελής.

2.2 Know-how (τέχνη): Guiding the construction of a cabinet is the carpenter’s know-how (τέχνη).

The process begins with the carpenter’s prior projection of an idea of the outcome, the εἶδος προαιρετόν that will function as the τέλος of the activity.
The wood that has been selected as appropriate (geeignet) for the task then undergoes a process of appropriation (Eignung) to being a cabinet.
In this case the process is guided not by an internal τέλος, as with the acorn, but by the external τέλος residing in the mind of the carpenter who first projected the outcome (GA 9: 191-93).

4. In short, Eignung names the reality of a something that is in the process of being brought-ad-proprium, still coming into its proper status as complete and whole.