
577 N.W.2d 897 (1998)
Fred J. GLANCY, Plaintiff-Appellee,
v.
CITY OF ROSEVILLE, a municipal corporation, Defendant-Appellant.
Frances C. ASHTON and James ASHTON, Individually, Plaintiffs-Appellees,
v.
CITY OF HAZEL PARK, a municipal corporation, Defendant-Appellant.
Docket Nos. 106283, 109241, Calendar Nos. 1-2.
Supreme Court of Michigan.
Argued March 3, 1998.
Decided June 9, 1998.
*899 Bieber & Czechowski, P.C. by Walter J. Czechowski and William J. Brady, Center Line, for plaintiff-appellee Glancy.
Granzotto & Nicita, P.C. by Mark Granzotto, Detroit, and Law Office of Ronald A. Steinberg by Ronald A. Steinbergtern, Farmington Hills, for plaintiffs-appellees Francis C. Ashton and James Ashton.
Plunkett & Cooney, P.C. by Mary Massaron Ross, Detroit, for defendants-appellants.
Granzotto & Nicita, P.C. by Angela J. Nicita, Detroit, amici curiae, for Michigan Trial Lawyers Association.
Johnson, Rosati, Galica, Labarge, Aseltyne & Field, P.C. by Marcia L. Howe, Farmington Hills, amici curiae, for Michigan Municipal League.


*898 OPINION
TAYLOR, Justice.
These cases present the issue whether the second sentence of M.C.L. § 691.1407(1); M.S.A. § 3.996(107)(1), which affirms governmental immunity as it existed before July 1, 1965, codified the "two-inch rule"[1] regarding municipal liability for sidewalk defects despite this Court's abolition of the two-inch rule in Rule v. Bay City, 387 Mich. 281, 195 N.W.2d 849 (1972). Because the two-inch rule is a negligence rule rather than a principle of governmental immunity, we hold that subsection 7(1) could not reinstate the two-inch rule. Regarding defendants' alternative contention that this Court should adopt the two-inch rule as a threshold for lack of "reasonable repair" under M.C.L. § 691.1402(1); M.S.A. § 3.996(102)(1), we hold that such arguments are properly directed to the Legislature.

Facts and Proceedings
These two cases arise out of slip and fall accidents involving sidewalk defects of less than two inches. In Glancy, the portion of sidewalk at issue was between 1¼ and 1½ inches higher than the surrounding sidewalk. In Ashton, the sidewalk portion at issue was between 1 and 1½ inches higher than the surrounding sidewalk. Defendants in both cases moved for summary disposition under MCR 2.116(C)(7) and (10), contending that subsection 7(1) reinstated the two-inch rule. In each case, the trial court granted defendant's motion for summary disposition, concluding that subsection 7(1) codified the two-inch rule into Michigan law. In Glancy, the Court of Appeals reversed, concluding that subsection 7(1) only preserved pre-1965 immunity for the state, not other governmental entities, i.e., municipalities. Glancy v. Roseville, 216 Mich.App. 390, 549 N.W.2d 78 (1996). In Ashton, the Court of Appeals reversed on the basis of Glancy. Ashton v. Hazel Park, unpublished memorandum opinion of the Court of Appeals, issued April 4, 1997 (Docket No. 182876).

Standard of Review
Appellate review of a trial court ruling on a motion for summary disposition is de novo. Spiek v. Dep't of Transportation, 456 Mich. 331, 337, 572 N.W.2d 201 (1998). "MCR 2.116(C)(7) tests whether a claim is barred because of immunity granted by law, and requires consideration of all documentary evidence filed or submitted by the parties." Wade v. Dep't of Corrections, 439 Mich. 158, 162, 483 N.W.2d 26 (1992).
MCR 2.116(C)(10) tests the factual support of a plaintiff's claim. The court considers the affidavits, pleadings, depositions, admissions, and other documentary evidence submitted or filed in the action to determine whether a genuine issue of any material fact exists to warrant a trial. [Spiek, supra at 337, 572 N.W.2d 201.]


*900 I. Municipality Liability for Sidewalk Defects

The governmental tort liability act, M.C.L. § 691.1401 et seq.; M.S.A. § 3.996(101) et seq., provides governmental immunity for governmental agencies, including municipalities like defendants here. "[T]he heart of the act, § 7, provides for broad immunity from tort liability for governmental agencies engaged in governmental functions." Wade, supra at 166, 483 N.W.2d 26. "[E]xceptions to governmental immunity are to be narrowly construed." Id. M.C.L. § 691.1402(1); M.S.A. § 3.996(102)(1) sets forth the "highway exception" to governmental immunity. Subsection 2(1) states in pertinent part:
Each governmental agency having jurisdiction over a highway shall maintain the highway in reasonable repair so that it is reasonably safe and convenient for public travel. A person sustaining bodily injury or damage to his or her property by reason of failure of a governmental agency to keep a highway under its jurisdiction in reasonable repair, and in condition reasonably safe and fit for travel, may recover the damages suffered by him or her from the governmental agency.
Subsection 2(1) requires municipalities to maintain sidewalks in "reasonable repair."[2] Under the two-inch rule, sidewalk defects of two inches or less did not constitute a lack of "reasonable repair" as a matter of law. See Weisse v. Detroit, 105 Mich. 482, 483, 487, 63 N.W. 423 (1895); Harris v. Detroit, 367 Mich. 526, 528, 117 N.W.2d 32 (1962). In 1972, Rule, supra, abolished the two-inch rule.

II. Affirmation of Pre-1965 Governmental Immunity
Subsection 7(1) of the governmental tort liability act, as amended in 1986, provides:
Except as otherwise provided in this act, all governmental agencies shall be immune from tort liability in all cases wherein the government agency is engaged in the exercise or discharge of a governmental function. Except as otherwise provided in this act, this act shall not be construed as modifying or restricting the immunity of the state from tort liability as it existed before July 1, 1965, which immunity is affirmed.
The second sentence of subsection 7(1) "retains preexisting governmental immunity law except where provided otherwise in the act" and mandates an historical approach. Hadfield v. Oakland Co. Drain Comm'r, 430 Mich. 139, 147, 170, 422 N.W.2d 205 (1988).
By its terms, this provision of subsection 7(1) applies to "the state." M.C.L. § 691.1401; M.S.A. § 3.996(101) provides distinct definitions of "state" and "municipal corporation" and defines "governmental agency" to include both. In the context of the first sentence of subsection 7(1), which uses the term "governmental agencies," the use of the term "the state" in the second sentence might be read to indicate that this provision applies only to the state, not to governmental agencies generally.
However, in Li v. Feldt (After Remand), 434 Mich. 584, 592-593, n. 8, 456 N.W.2d 55 (1990), which involved tort liability of municipalities, this Court stated that § 7 should be read to put "all agencies of government on the same footing with regard to tort liability." This Court noted that the stated purpose of the governmental tort liability act is to "make uniform the liability of municipal corporations, political subdivisions, and the state ... when engaged in the exercise or discharge of a governmental function." Id. In Hadfield, supra at 168-169, 422 N.W.2d 205, which involved actions against a county and municipality as well as the state, this Court recognized a trespass-nuisance exception to governmental immunity on the basis of the historical approach mandated by § 7. These authorities indicate that the second sentence of subsection 7(1) applies to all governmental agencies, not just the state, despite the use of the term "the state" in this provision.
The present case does not require this Court to reconsider whether these authorities *901 accord with the statutory language of subsection 7(1). Rather, this Court may assume, without deciding, that this provision of subsection 7(1) applies to municipalities because this provision would not affect the two-inch rule.

III. Whether the Two-inch rule is a Governmental Immunity Principle That Subsection 7(1) Would Affirm
Here, defendants contend that the second sentence of subsection 7(1) mandates the continued application of the two-inch rule despite this Court's abolition of it in 1972. The basis of the two-inch rule is the concept of "reasonable repair." The highway exception, subsection 2(1) of the governmental tort liability act, subjects governmental agencies to liability when they fail to maintain highways in "reasonable repair." The two-inch rule was a bright-line rule stating that defects of two inches or less constituted "reasonable repair" as a matter of law.
The roots of the two-inch rule can be traced to Weisse, supra, which involved injuries allegedly arising out of a defective crosswalk. The Weisse Court noted that, in 1887, the Legislature amended the statute, imposing a duty on municipalities to maintain highways so that it required "reasonable repair" rather than "good repair" and imposed a duty that streets be "reasonably safe," not absolutely safe. 105 Mich. at 486-487, 63 N.W. 423. The Weisse Court concluded that the street at issue was reasonably safe despite the alleged defect of approximately two inches and held that the trial court should have given the defendant's request to charge that "as a matter of law that no such defect existed as authorized a recovery." Id. at 483, 63 N.W. 423.
In Rule, supra at 283, 195 N.W.2d 849, this Court abolished the two-inch rule:
[W]e will no longer hold as a matter of law that a depression or obstruction of two inches or less in a sidewalk may not be the basis for a municipality's liability for negligence.
In abolishing the two-inch rule, the Rule Court relied on Justice Adams' dissent in Harris, supra. Justice Adams stated that the two-inch rule "gradually hardened into a rule of law that where a defect in a walk was less than 2 inches in depth, the walk would be considered to be safe and the city free from negligence." 367 Mich. at 531, 117 N.W.2d 32 (emphasis added). He agreed with Colorado authority indicating that it is improper to determine "actionable negligence" by an arbitrary measurement and concluded that the facts and circumstances of each case must be considered to determine if there is an issue to submit to the jury regarding whether the defendant is negligent. Id. at 535-536, 117 N.W.2d 32.
As this Court has previously noted, tort actions against governmental agencies generally raise two separate issues: 1) whether the plaintiff has pleaded a cause of action in avoidance of governmental immunity, and 2) whether the plaintiff can establish the elements of a negligence action.[3] Whether a defect is over two inches bears on the issue of negligence, i.e., whether the municipality failed to keep the sidewalk in "reasonable repair." The cases applying the two-inch rule as well as those abolishing it indicate that the two-inch rule barred recovery because a plaintiff would be unable to prove actionable negligence, i.e., lack of "reasonable repair," rather than because a municipality was governmentally immune from liability for defects of two inches or less. Thus, the two-inch rule was not a rule of common-law immunity; rather, it was a common-law threshold for negligence based on the "reasonable repair" standard of care of the statutory highway exception.[4]
*902 The two-inch rule's relationship to the statutory highway exception distinguishes it from common-law principles of immunity like the trespass-nuisance exception recognized in Hadfield, which are properly the subject of the second sentence of subsection 7(1). By its terms, this provision of subsection 7(1) affirms pre-1965 common-law immunity that is not addressed by the governmental tort liability act. There is no need to resort to pre-1965 common law with respect to the statutory exceptions explicitly set forth in the act. For these reasons, subsection 7(1) would not resuscitate the two-inch rule after this Court abolished it in Rule.
Moreover, even with respect to immunity principles, subsection 7(1) does not preserve governmental immunity law in a time capsule as of July 1, 1965. Subsection 7(1) states that the act "shall not be construed as modifying or restricting" immunity as it existed before July 1, 1965. But this provision does not prohibit this Court from reconsidering and amending or abolishing pre-1965 precedent regarding governmental immunity. In Ross v. Consumers Power Co. (On Rehearing), 420 Mich. 567, 609, 363 N.W.2d 641 (1984), this Court reiterated that "`to read the second sentence of [subsection 7(1) ] as "preserving for all time state governmental immunity heretofore recognized by case-law" would be to "assume that the Legislature failed to recognize that the evolution of case law precedent is exclusively committed to the judicial branch of government."'"[5]

IV. Whether to Adopt the Two-inch rule Under Subsection 2(1)
Alternatively, defendants argue that even if subsection 7(1) did not codify the two-inch rule, this Court should adopt the two-inch rule as a threshold for lack of "reasonable repair" under subsection 2(1). In support of adopting the two-inch rule, defendants cite the great expense to municipalities of defending lawsuits for injuries arising out of sidewalk defects of two inches or less. The Legislature, with its ability to consider testimony from a variety of sources and make compromise decisions, is much better positioned than the judiciary to consider such policy arguments and make policy choices.[6] "The responsibility for drawing lines in a society as complex as oursof identifying priorities, weighing the relevant considerations and choosing between competing alternativesis the Legislature's, not the judiciary's." O'Donnell v. State Farm Mut. Automobile Ins. Co., 404 Mich. 524, 542, 273 N.W.2d 829 (1979). "Under the Michigan Constitution and its division of power between the Legislature and the judiciary, [the judiciary is] only authorized to implement statutes, not change them in response to policy arguments, regardless of how persuasive." Miller v. Riverwood Recreation Center, Inc., 215 Mich.App. 561, 563, 546 N.W.2d 684 (1996). In other words, while the judiciary has authority to formulate policy regarding common-law issues, which could include adopting a bright-line rule, it may not adopt rules that change statutes on the basis of policy arguments. Rather, the judiciary's role in determining the policy behind a statute is to attempt to determine the policy choice the Legislature made. In subsection 2(1), the Legislature set forth a duty of "reasonable repair." Policy arguments regarding adoption of a bright-line rule that defects of two inches or less do not constitute a lack of "reasonable repair" under subsection 2(1) should be directed to the Legislature. Moreover, even if we were to consider these policy arguments, they would be unavailing because defendants fail to meet the great burden incumbent upon them to overcome the presumption in favor of the validity of our past holding in Rule. See Brown v. Manistee Co. Rd. Comm., 452 Mich. 354, 365-366, 550 N.W.2d 215 (1996), regarding stare decisis.

Conclusion
For these reasons, we affirm the Court of Appeals decisions in both Glancy and Ashton. *903 While we agree with the result in both cases, we analyze the issues differently than did the Court of Appeals. The two-inch rule is a rule of negligence, not a common-law principle of governmental immunity that the second sentence of subsection 7(1) would codify. Policy arguments in favor of adopting the two-inch rule as a bright-line threshold for lack of "reasonable repair" under subsection 2(1) should be addressed to the Legislature.
MALLETT, C.J., and BRICKLEY, BOYLE, and WEAVER, JJ., concur with TAYLOR, J.
MARILYN J. KELLY, Justice (concurring in part and dissenting in part).
I concur with the result reached by the majority, and with much of its reasoning. However, I cannot join part IV of today's opinion.
Defendants argue that, if we find that the two-inch rule was not revived by statute, we should revive the two-inch rule ourselves. I agree with the majority's conclusion that we should not revive the two-inch rule at this time. I reach that decision, not because the Court lacks the power to revive the rule, but because defendants have not persuaded us that our decision in Rule was incorrect. Op. at 903.
I dissent because the majority, in an alternate position, rejects defendants' argument that the Court should adopt the two-inch rule because it would be unconstitutional to do so. I agree that, in areas properly within the province of the Legislature, the Court may not formulate its own public policy and, on that basis, change a statute. However, nothing in the opinion convinces me that reviving the two-inch rule would violate that limitation, and therefore, I cannot join the portion of the opinion that implies as much. I hesitate to construe limitations placed on this Court by our constitution where it is not necessary to do so.
MICHAEL F. CAVANAGH, J., concurs with MARILYN J. KELLY, J.
NOTES
[1]  This Court articulated the two-inch rule as "a depression in a walk which does not exceed 2 inches in depth will not render a municipality liable for damages incident to an accident caused by such depression." Harris v. Detroit, 367 Mich. 526, 528, 117 N.W.2d 32 (1962).
[2]  Subsection 2(1) specifically states that the duty of the state and counties to maintain highways does not include "sidewalks, crosswalks, or any other installation outside of the improved portion of the highway designed for vehicular travel."
[3]  See, e.g., Canon v. Thumudo, 430 Mich. 326, 335, 422 N.W.2d 688 (1988) ("Courts should take care not to confuse their separate inquiries into immunity and negligence").
[4]  In further support of the proposition that the two-inch rule bears on negligence rather than governmental immunity, the Ashton plaintiff notes that this Court has at least considered the two-inch rule in the context of actions against nongovernmental defendants. See Crowe v. Michigan Central R Co., 142 Mich. 692, 106 N.W. 395 (1906); Sherman v. Consumers' Power Co., 199 Mich. 543, 165 N.W. 844 (1917). The Ashton plaintiff also notes that Williams v. Detroit, 364 Mich. 231, 111 N.W.2d 1 (1961), abolished common-law governmental immunity for municipalities. That it was still necessary for this Court to abolish the two-inch rule in Rule in 1972, after Williams, indicates that the two-inch rule is a rule of negligence, not a principle of immunity.
[5]  The version of subsection 7(1) applied in Ross affirmed immunity "as it existed heretofore"; in 1986 this portion of the statute was amended to "as it existed before July 1, 1965."
[6]  An example of the adoption of a bright-line rule by statutory presumption is M.C.L. § 257.625a(9); M.S.A. § 9.2325(1)(9).
