The opinion of the court was delivered, by
Strong, J.The defendants below, now plaintiffs in error, were supervisors of two adjoining townships, the line between which was a small stream. Acting under an order of the Court of Quarter Sessions, they made a new road which had been laid out across the stream, and instead of building a bridge over it, they made a passage-way by depositing stone in its bed, which the plaintiff below complains obstructed the flow of water to his mill. For this he has brought this suit against them, and he seeks to charge them personally with the damages which he has sustained in consequence of the alleged obstruction.
On the trial in the court below, the jury were correctly instructed that township officers are not personally liable for acts done honestly in the exercise of the discretion which the law gives them, even though that discretion be exercised so mistakenly as to work an injury to private property or to private individuals. It is an undeniable principle that neither the state itself nor any persons natural or artificial, acting under its authority, are responsible for any damages occasioned by the construction of a highway, unless provision has been made for *216compensation. The doctrine was broadly asserted in The Governor and Company of the British Plate Manufacturers v. Meredith, 4 Term Rep. 794, in Boulton v. Crowther, 2 Barn. & Cress. 703, and it has ever since been maintained in the English courts. It is equally well settled in this Commonwealth. It was asserted in Green v. The Borough of Reading, 9 Watts 382, in The Monongahela Navigation Company v. Koons, 6 W. & S. 101, in Henry v. The Pittsburgh Bridge Company, 8 Id. 85, in O’Connor v. Pittsburgh, 6 Harris 187, and in very many other cases which might be cited. The public officer is protected, however, only while acting within the limits of his authority. If under the colour of his office he exceeds the power which the law has conferred upon him, he cannot shelter himself under the plea that he is a public agent. The first question in any case brought against him, therefore, is whether he had legal authority for the acts complained of. And indeed it was held in The Mayor v. Randolph, 4 W. & S. 514, that no other question could arise. In that case Judge Sergeant said, that while the agent of the state acts within the sphere of his authority, his motives or the cause of his action are not examinable. He seemed to regard it of no consequence whether the motive which prompted to the action was to promote the wishes of one man or others, or whether it was to carry out the objects of the law. In his mind it was a mere question of power. There is no small reason for holding that the liability of a public agent to make or repair a highway for damages caused by his acts, done in pursuance of his public trust, should not begin until he has transcended his powers. In most of the cases the suitor against him complains of a nuisance. Whether an act done be a nuisance or not involves. always the inquiry whether it was contrary to law. It cannot be a nuisance if legally authorized, and to the inquiry whether legally authorized or not, the motives of the actor are quite irrelevant. Human law, except in very few cases, looks only to external conduct. Besides, if the motive with which the erection of a bridge or a causeway, an excavation or an embankment, was done, is to determine whether it be a nuisance or not, the most strange results would be accomplished. Then if the motive of the agent be bad, the work done must be undone, though its undoing be itself in direct violation of law. The party injured may sue until the nuisance be abated. No statutory remedy has been provided which assesses in one action the damages for the erection and maintenance of a nuisance.
Yet it seems to be established that if a public officer acts maliciously or wantonly; if the work which he performs be done rather to injure a private individual than to discharge a public duty; he is responsible for the consequences. He cannot recklessly, wantonly, or maliciously invade private rights, and pro*217tect himself under the authority of the law. He is not allowed to find shelter under'the wing of public authority when he is assailed for acts done for the gratification of his own malignant feelings, or with a wicked disregard of the interests of others. This principle was advanced in Boulton v. Crowther, in Jones v. Bird, 5 B. & Ald. 837, in Henry v. The Pittsburgh Bridge Company, and it is the admitted law of the Commonwealth. The Court of Common Pleas attempted to apply it to the trial of this case. But we think it was erroneously extended. The jury were instructed that the defendants were liable if in building the passage-way over the stream, there was an intent to injure the plaintiff: in other words, if they did not build a bridge as they might have done, but instead of doing so erected the causeway with the intent of injuring the plaintiff. Again the jury was charged that if the defendants constructed the causeway with an inters to injure the plaintiff, lie could recover, and that an intent to injure him might be inferred from the acts of the defendants, if the jury believed they wore such as could have been done with no other intent, or if the evidence justified the jury in drawing such an inference. From the whole case it is apparent that the marrow of the plaintiff’s complaint was that the supervisors did not build a bridge instead of a causeway. The latter was more hurtful to the plaintiff than a bridge would have been. The obvious impression made by the charge of the court was, therefore, that building a causeway rather than a bridge, was an act done with intent to injure the plaintiff, for as the hurt resulting from the causeway was certain, and as it is fairly presumable that a person intends the natural consequences of his acts, the simple act of building the causeway indicated that intent, which, in the opinion of the court, subjected the defendants to liability for damages. This wa.s erroneous. The defendants could choose between a bridge and a causeway without exposure to a claim for damages. They were, authorized to decide deliberately to build a causeway, and consequently to work increased harm to the plaintiff, and still be protected by the public authority under which they acted. A mere intent to do an act which must work harm to the plaintiff was not enough to strip them of their shield. They were-defenceless only if their intent to injure the plaintiff was malicious, or so wanton and reckless as to prove that it was malicious. A mistake of judgment was not enough to make them liable to damages. Nor is a court and jury to review their judgment while they act within the scope of their authority. Such a measure of immunity to public officers the interests of society and the enforcement of the laws demand. The case before us well illustrates the importance of adhering firmly to this, old rule. We find no evidence in the case of any malice against the plaintiff below. That he was damnified may *218have been true, but the defendants have done no more than determine in the exercise of a discretion which the law gave them and commanded them to exercise, that it was better for the interests of the public committed to them to build a passage-way of stone than to erect a bridge. It is of the utmost importance that officers intrusted with such powers be protected in exercising them, without being terrified with the apprehension of personal responsibility, if their acts should result in harm to any private property. We think the charge of the learned judge of the Common Pleas was not sufficiently guarded. The jury should have been instructed that the plaintiff could not recover unless the defendants had acted with a malicious design to .do him injury, or with such a reckless and wanton disregard of his interests as would be equivalent to malicious intent. They are not personally liable because they built # causeway when they might have built a bridge.
There was no error in leaving to the jury to find that the injury, if any, was the joint act of the defendants. The erection of the causeway was one act, though parts of it were built at different times and by different defendants. It was all done in pursuance of a common design, and therefore the acts of one were the acts of all the agents.
But whether in doing the work each of the defendants had a malicious purpose to injure the plaintiff is another question, and to show that Taylor, one of the defendants, was actuated by no such motive, we think he should have been permitted to prove that before the passage-way ivas commenced, he had received a message from Tealy, the supervisor of Germany township, that he would not join in building a bridge; that the people of his township were opposed to it. Such evidence, as it supposed a motive for the choice of a causeway rather than a bridge, tended to disprove the existence in Taylor’s mind of any malice, and to account for his action without rendering necessary the imputation to him of any guilty design. Nor is it obnoxious to the criticism that it was making testimony for themselves. The message was sent before the act complained of was done. At all events it should have been submitted to the jury.
Judgment reversed, and a venire de novo awarded.