(dissenting). The events giving rise to the claims in this case are indeed tragic. See ante at 195 (Greaney, J., concurring in part and dissenting in part). But I respectfully disagree with the opinion of Justice Ireland (and the two Justices who join him) that would establish for the first time in this Commonwealth a physician’s duty to prevent harm to nonpatients, and would do so in sweeping terms. See ante at 184 (Ireland, J., concurring) (physician “owes a duty of care to all those foreseeably put at risk by his failure to warn about the *202effects of the treatment he provides to his patients”). I also cannot agree with Justice Greaney’s more cabined opinion that “a physician who has knowledge of a danger that may be posed to others from a patient’s decision to operate a motor vehicle while under the influence of prescribed medication . . . may be held liable for injuries to others caused by the failure to warn” the patient of the risks involved. Ante at 196 (Greaney, J., concurring in part and dissenting in part). In my view, the Superior Court judge properly granted summary judgment to Dr. Florio on the ground that he owed no duty to the decedent.
Justice Ireland would hold that “a physician owes a duty of reasonable care to everyone foreseeably put at risk by his failure to warn of the side effects of his treatment of a patient.” Ante at 190 (Ireland, J., concurring). The opinion is grounded on two false premises. First, as Justice Cordy describes, Justice Ireland conflates the “duty to warn” with the much more comprehensive “duty of care,” and thus vastly enlarges the field of physician liability. See post at 210 (Cordy J., dissenting). See also Restatement (Third) of Torts: Liability for Physical Harm § 41 comment h (Proposed Final Draft No. 1, 2005) (duty to warn is “more limited” than duty to use reasonable care). Second, Justice Ireland asserts that the physician liability to third parties he would impose falls readily within the penumbra of our decision in Cottam v. CVS Pharmacy, 436 Mass 316 (2002) (Cottam), where, according to Justice Ireland, “existing tort law already imposes on a doctor a duty to warn a patient of the adverse side effects of medications.” Ante at 191 (Ireland, J., concurring). Our existing tort law does not impose such a duty, and Cottam does not bear the weight Justice Ireland assigns it.
At issue in Cottam, among other things, was the interplay between, on the one hand, a patient’s need for information sufficient to give informed consent to prescribed medications and, on the other, a physician’s need for autonomy within the physician-patient relationship to act based on the physician’s reasoned professional judgment and his “knowledge of the patient’s medical history and unique condition.” Id. at 321. On this point we were careful to note that the physicians’ duty is “to inform themselves about the drag and warn their patients as they deem necessary.” Id. Lest there be any doubt of the scope of the duty, *203we further stated that physicians, after considering the history and needs of their patients and the quality of the drugs, are required “to inform their patients of those side effects they determine are necessary and relevant for patients to know in making an informed decision” (emphasis added). Id. Our statement of a doctor’s duty to his patient was precisely calibrated to protect patients from harm while avoiding judicial interference with the doctor-patient relationship.
By seeking to impose on doctors a duty to third parties that would require a physician to inform a patient of any and all side effects of any and all treatments of a patient, Justice Ireland does not limit his opinion to warnings of the potential side effects of prescription medications.1 See ante at 184, 190 (Ireland, J., concurring). Rather, his opinion stretches the narrow holding in Cottam beyond recognition. In doing so, he significantly shrinks the essential and protected space within which doctor and patient can freely move together. Gone would be the physician’s ability to exercise independent professional judgment about how to present treatment options to the patient. Gone would be the option to omit discussion of remotely possible adverse side effects. The physician’s concern for a patient’s ability to assess information about needed and appropriate treatment would be forced to compete with concern for an amorphous, but widespread, group of third parties whom a jury might one day determine to be “foreseeable” plaintiffs. The physician would be forever looking over his shoulder. Nothing in Cottam, a case of informed consent, portends *204the effort to impose such blanket expansion of doctors’ liability to third parties.2
Justice Greaney’s more restrained analysis of the scope of a doctor’s liability to nonpatients3 also is not supported by the conclusion or rationale of Cottam. To hold, as Justice Greaney would, that a physician is obligated by a duty to third parties to warn a patient against driving when “a physician . . . has knowledge of a danger that may be posed to others from a patient’s decision to operate a motor vehicle while under the influence of prescribed medication,” ante at 196 (Greaney, J., concurring in part and dissenting in part), is effectively to dictate that a physician forbid a patient from engaging in any “hazard-pus activities” including operating a motor vehicle or heavy machinery, ante at 198 n.2 (Greaney, J., concurring in part and dissenting in part) while taking the prescribed medication, regardless of whether, in the physician’s professional opinion, such a warning is necessary or wise in the individual patient’s circumstances.4 Cf. Cottam, supra at 321 (discussing physician’s duty *205“to inform their patients of those side effects they determine are necessary and relevant for patients to know in making an informed decision”).
For the reasons detailed by Justice Cordy in his dissent, I also reject Justice Greaney’s premise that the physician’s purported duty to a nonpatient radiates from the “special relationship” of physician to patient. See post at 207 n.3 (Cordy, J., dissenting). See also ante at 197-198 (Greaney, J., concurring in part and dissenting in part). Indeed, McKenzie v. Hawai’i Permanente Med. Group, Inc., 98 Haw. 296 (2002), relied on by Justice Greaney, see ante at 199 (Greaney, J., concurring in part and dissenting in part), expressly disavows the “special relationship” analysis as “inapplicable” in a case with strikingly similar facts. Id. at 300. See Restatement (Third) of Torts: Liability for Physical Harm § 41 comment h (Proposed Final Draft No. 1, 2005) (“The physician-patient relationship is not among the relationships listed in this Section as creating an affirmative duty”).
Finally, I fail to see how the unwarranted extension of judicial power suggested by the concurring opinions is cured by Justice Ireland’s invitation to the Legislature to fix the result reached today. Ante at 192 (Ireland, J., concurring) (“I would leave to the Legislature the task of determining whether to impose further limits on doctors’ liability”). The invitation reverses the appropriate roles of the legislative and judicial branches. It is for the court to proceed incrementally with the expansion of common-law tort principles, and for the Legislature to initiate, if it chooses, the policy process of comprehensive tort reform. One need not be clairvoyant to understand the inevitable result of today’s enlargement of liability: a significant increase in third-party litigation against doctors and an attendant increase in *206expenses at a time when our health care system is already overwhelmed with collateral costs. The contrasting opinions issued today suggest just how widely and thoroughly reasonable minds may differ on this matter of broad social import.
Today’s result impedes not only the work of doctors. It impedes the work of our courts. On remand, the trial judge is left the unenviable task of divining from the vague generalizations of the concurring opinions the outer limits of a novel duty of physicians to third-party nonpatients. Because I agree with the trial judge that the physician’s liability does not extend to the third-party decedent in this case, I would uphold the grant of summary judgment in Dr. Florio’s favor, and not leave it to trial judges to puzzle their way through this thorny issue of public policy.
Cottam v. CVS Pharmacy, 436 Mass. 316 (2002) (Cottam), does not impose a duty on a physician to warn his patient of every side effect of every drug he prescribes, let alone every treatment he recommends. Justice Ireland declares that he does “not imply that Dr. Florio owed a duty to Coombes [the decedent] to warn of every side effect of every drug he prescribed,” ante at 193 (Ireland, J., concurring), but only that Dr. Florio had some (unspecified) duty to give some (unspecified) warnings to his patient in light of “the number and nature of drugs prescribed, the age and health of the patient, and the earlier assurance about the ability of the patient to drive,” id. This purported qualification creates confusion at the very point where clarity is required. Which side effects of which drugs could Dr. Florio have ignored? What difference does his patient’s age make? Lacking clarity about the scope of the required duty to warn, physicians would proceed at their peril if they exercised their professional judgment to warn a patient only of side effects of prescription medicatians they “deem necessary.” Cottam, supra at 321.
As described more folly by Justice Cordy, post at 213 n.6 (Cordy, J., dissenting), the breadth of Justice Ireland’s conclusion that any treatment — even those not involving prescription medications — imposes a “duty of care” to third parties is unsupported by the cases from other jurisdictions on which he relies. See, e.g., McKenzie v. Hawai’i Permanente Med. Group, Inc., 98 Haw. 296, 308 (2002) (“we believe that a logical reason exists to impose upon physicians, for the benefit of third parties, a duty to advise their patients that a medication may affect the patient’s driving ability when such a duty would otherwise be owed to the patient”); Joy v. Eastern Me. Med. Ctr., 529 A.2d 1364, 1366 (Me. 1987) (“when a doctor knows, or reasonably should know that his patient’s ability to drive has been affected [by prescribed medications], he has a duty to the driving public as well as to the patient to warn his patient of that fact”); Hardee v. Bio-Medical Applications of S.C., Inc., 370 S.C. 511, 516 (2006) (recognizing physician’s duty to “the motoring public” to warn patient of risks of operating motor vehicle arising from physician’s treatment); Burroughs v. Magee, 118 S.W.3d 323, 333 (Tenn. 2003) (physician owed duty of care to patient and to members of motoring public to warn patient “of the possible adverse effect of the two prescribed drugs on his ability to safely operate a motor vehicle”).
The duty proposed by Justice Greaney would be imposed only on physidans who prescribed medications that the physician has reason to know may affect the patient’s ability to drive a motor vehicle safely. Ante at 196 (Greaney, J., concurring in part and dissenting in part).
The attempt to limit the duty Justice Greaney would impose on physicians, i.e., that a physician should give a warning “consistent with the manufacturer’s warning” and that a physician should warn a patient that he “should not *205drive, or operate heavy machinery, until the patient knows how he or she will react” to a particular prescribed medication, ante at 198 n.2 (Greaney, J., concurring in part and dissenting in part), does not in fact place any boundaries around the duty he would recognize. The appropriateness of a physician’s warning will always be called into question when a third party is injured. In this case there is evidence that the patient had driven without difficulty while taking the prescribed medications. Under Justice Greaney’s formulation the jury will now be permitted, indeed required, to delve into the nature of the warning given and to determine for themselves whether it was adequate, imposing liability on a physician who may have given a warning but one the jury deem not adequate.