Don famously did this list: a double dose, initially, of philosopher! (4,2,9)
I believe the answer is:
tilt at windmills
'don famously did this' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.
'list a double dose initially of philosopher' is the wordplay.
I cannot quite understand how this works, but
'list' could be 'tilt' (both can mean to lean) and 'tilt' is found in the answer.
'a' is found in the answer.
'double' could be 'twin' (I've seen this before) and 'twin' is located in the answer.
'philosopher' could be 'mill' (I've seen this before) and 'mill' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for tilt at windmills that I've seen before include "Fight an imaginary enemy (as Don Quixote did)" , "Act quixotically" , "Attack imaginary enemies or evils" .)