Philosopher errs, last blunder being awful (8,7)

I believe the answer is:

bertrand russell

'philosopher' is the definition.
(Bertrand Russell is an example)

'errs last blunder being awful' is the wordplay.
'being awful' is an anagram indicator.
'errs'+'last'+'blunder'='errslastblunder'
'errslastblunder' with letters rearranged gives 'BERTRAND RUSSELL'.

(Another definition for bertrand russell that I've seen is " Mathematician".)

I've seen this clue in The Telegraph.

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