Doctor vs Mechanic

Once Doctor went to mechanic to get ready his car .

Mec : Hi doc we two are doing same profession you repair spare part of human . me machine
        
doc : yes what for that .

Mec : but you people are treated as high equal to god among the people than us . why is it so?

doc :  Yes , can you repair the spare when the engine is running . so only we are at the position.