In cases like this, the shock probably comes too abruptly to enable the man to prepare himself to receive it.

The efficacy of a little preparation, even preparation lasting but a few seconds, is worthy of remark.

Two theories connecting fear and trembling may be noted here: one that a person trembles because he fears; the other, and later, that trembling is automatic, and that a person fears _because he trembles_.
But the influence of fear is not only to tempt a man to turn his back on duty and seek safety in flight, for it affects him in many degrees short of this.

Sometimes, in fact usually, it prevents the accurate operation of the mind in greater or less degree.

Here again training comes to the rescue, by so habituating a man to do his work in a certain way (loading a gun for instance) that he will do it automatically, and yet correctly, when his mind is almost paralyzed for a time.