The solidity of a strong nervous system is the puppy's first defense against the challenges life will place in its path. Nerve is the ability to roll with the punches. Unexpected changes in the pup's environment will not shake its calm and youthful curiosity if these are housed in a strong nervous system to begin with. As it grows, the puppy with sound nerve will emerge as a confident dog, willing to please its owner. Panic it unknown to this dog and fear does not bring a bite reaction.
Nerve is the critical factor in working dog temperament.
Because of its significance in the whole working temperament, no excuse should be tolerated when it is lacking. A dog without nerve or with weak nerve should just not be bred. Neither should such a dog be forced to work when its basic constitution has not fitted it with this necessary requirement. A dog with poor nerve should be allowed to live its life as a pet in a non-threatening environment. Even a superb physical specimen of excellent conformation, coat and color should be rejected for breeding if it exhibits the signs of a weak nervous system.