The most common and most likely answer to this crossword clue is the 5 letter word RODIN
I've seen this crossword clue in The Times
R
O
D
I
N
More clues leading to the result RODIN
- Thinker was his god at Russell's instigation
- Stick with popular French form master
- Stick in the name of a sculptor
- Creator of works endlessly crumbling away
- Artist‘s country escaping Roman god
- Bar popular sculptor
- Stick in a sculptor as the answer
- Bar popular French artist manually
- One to show man embracing woman
- Staff at home for French master
Buddy explains!

The straight part
We know that "Thinker was his" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case thinker was his = rodin.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.