Default standard of care
The test by which to determine the existence of negligence in a particular case may be stated as follows: Did the defendant in doing the alleged negligent act use that person would have used in the same situation? If not, then he is guilty of negligence. The law here in effect adopts the standard supposed to be supplied by the imaginary conduct of the discreet paterfamilias of the Roman law. The existence of negligence in a given case is not determined by reference to the personal judgment of the actor in the situation before him. The law considers what would be reckless, blameworthy, or negligent in the man of ordinary intelligence and prudence and determines liability by that.
The question as to what would constitute the conduct of a prudent man in a given situation must of course be always determined in the light of human experience and in view of the facts involved in the particular case. Abstract speculations cannot here be of much value but this much can be profitably said: Reasonable men govern their conduct by the circumstances which are before them or known to them. They are not, and are not supposed to be, omniscient of the future. Hence they can be expected to take care only when there is something before them to suggest or warn of danger. Could a prudent man, in the case under consideration, foresee harm as a result of the course actually pursued? If so, it was the duty of the actor to take precautions to guard against that harm. Reasonable foresight of harm, followed by ignoring of the suggestion born of this prevision, is always necessary before negligence can be held to exist. Stated in these terms, the proper criterion for determining the existence of negligence in a given case is this: Conduct is said to be negligent when a prudent man in the position of the tortfeasor would have foreseen that an effect harmful to another was sufficiently probable to warrant his foregoing conduct or guarding against its consequences. (G.R. No. L-12219. March 15, 1918)
The question as to what would constitute the conduct of a prudent man in a given situation must of course be always determined in the light of human experience and in view of the facts involved in the particular case. Abstract speculations cannot here be of much value but this much can be profitably said: Reasonable men govern their conduct by the circumstances which are before them or known to them. They are not, and are not supposed to be, omniscient of the future. Hence they can be expected to take care only when there is something before them to suggest or warn of danger. Could a prudent man, in the case under consideration, foresee harm as a result of the course actually pursued? If so, it was the duty of the actor to take precautions to guard against that harm. Reasonable foresight of harm, followed by ignoring of the suggestion born of this prevision, is always necessary before negligence can be held to exist. Stated in these terms, the proper criterion for determining the existence of negligence in a given case is this: Conduct is said to be negligent when a prudent man in the position of the tortfeasor would have foreseen that an effect harmful to another was sufficiently probable to warrant his foregoing conduct or guarding against its consequences. (G.R. No. L-12219. March 15, 1918)