in securing their own goods and chattels." [1] In some cases the law punishes even slight neglect, in others ordinary, in others only gross neglect. The omission of that care which the law requires in the case is called juridical fault, and after sentence there will be an obligation in conscience to make good damage caused through juridical fault, for the laws prescribing this are just, inasmuch as they make men more careful and conduce to the public good.
If something has been done without foreseeing that it would cause damage to another, but this danger was noticed before the damage actually took place, there will be an obligation in justice for him who performed the action to prevent the damage as far as he can; if he does not do this, he will be bound to restitution. For as long as he can prevent the evil consequences of his action, this is under his control, and may, from the point of view of morals, be considered as continuing, and thus, unless he prevents the evil when he can do so, the agent is the voluntary cause of it. If, however, he cannot prevent the damage without relatively serious inconvenience to himself, there is just cause for excusing him. And so, if I inadvertently throw a lighted match on the ground, and then notice that it may probably cause a conflagration with loss to others, I am bound in justice to extinguish the light, otherwise I must repair the damage done.
If slight negligence caused slight damage to another, there will be an obligation of repairing it under pain of venial sin. If slight negligence caused serious loss to another, there is a difficulty as to whether before any judicial sentence there be an obligation to make restitution. Many theologians deny that there is, for no grave obligation can arise from a slight fault, and a light obligation has no proportion to serious matter; there cannot be a light obligation to avoid homicide, for example. [2]
(b) In order that there may be an obligation to make restitution for causing damage to another, the damage must be really and objectively unjust. If damage to another follows from the lawful exercise of my rights, I am not bound to make it good. If I dig a well in my property and thereby deprive my neighbour of his supply of water, I am not bound to make restitution for the damage. Similarly, I may sell a new machine or invention, though it may indirectly cause loss to many who had on sale machines of older pattern for which
