In other words, he was unwilling to treat this as anything but a concrete problem, and he was used to camels being in villages, and he was quite unable to use the hypothetical, to ask himself what if there were no camels in Germany.
Ou seja, ele estava  relutante em encarar aquilo sob outro aspeto que não fosse  um problema concreto. Estava habituado a camelos  em aldeias pequenas e era totalmente incapaz de  fazer um raciocínio hipotético, de se interrogar se havia  ou não camelos na Alemanha.