### Clue: On reflection, nothing about British in Isaiah, say? (6)
### Answer: BERLIN 
 ### Explanation: Definition: Isaiah, say
 **Reversal of**(On reflection) [ NIL(nothing;zero) + RE(about;with reference to) + B(abbrev. for "British") ].
Defn: One;say, whose first name was Isaiah.
Answer: Russo-British philosopher.