delivered the Opinion of the.Court.
The question in this case is whether the. General Assembly can add qualifications for holding constitutionally created offices in addition to those set forth in the constitution itself. The trial court concluded that it could and thus, entered a permanent injunction prohibiting Pat Reale, the elected assessor of Adams County, from continuing to hold the office of Adams County Assessor. We reverse and remand with directions to dismiss the complaint.
I
In 1990, the General Assembly passed the Real Estate Appraiser’s Act, §§ 12-61-701 to -717, 5B C.R.S. (1991) (the Act), which requires, among other things, that real estate appraisers meet state licensing requirements and that county assessors be licensed.1 The *1206Act establishes categories of registered, licensed, and certified appraisers. Pursuant to section 12-61-706, 5B C.R.S. (1994 Supp.), county assessors must obtain an appraiser’s license by completing a minimum of fifty-five hours of classroom instruction and passing a standardized appraiser’s examination.2 The Act requires that county assessors comply with the licensing requirements within one year after taking office. § 12-61-714(2), 5B C.R.S. (1991). Reale has not met these requirements.
The State Board of Real Estate Appraisers (the Board) is charged with enforcing the Act. In 1993, the Board filed an action in the district court and requested a preliminary injunction seeking to prevent Reale from performing the duties of his office on the grounds that under the Act, he was not able to do so legally. In response, Reale argued, inter alia, that the Act was unconstitutional because the General Assembly did not have the power to impose additional qualifications for holding a constitutionally created office other than those set forth in the constitution itself.
The trial court declined to issue a preliminary injunction. However, after a trial on the merits, the court concluded that the Act served a compelling state interest, i.e., fair and accurate tax assessments, and was constitutional. Further, it held that the Act did not violate the guarantee of equal protection under the law and that the court was empowered to enjoin Reale from holding office. It entered a permanent injunction barring Rea-le from holding office as Adams County Assessor.
On appeal Reale reiterates his qualification argument and also contends that the licensing requirements of the Act violate his right to equal protection of the law.3
lí
The office of county assessor is created by article XIV, section 8 of the Colorado Constitution. Article XIV, section 10 of the Colorado Constitution provides: “No person shall be eligible to any county office unless he shall be a qualified elector; nor unless he shall have resided in the county one year preceding his election.” Thus, the question presented is whether the qualifications for holding the office of county assessor provided for in article XIV, section 10 are exclusive, or whether the General Assembly may impose additional qualifications. Because we hold that the General Assembly may not impose additional qualifications as a prerequisite to holding the office of county assessor, we need not address Reale’s equal protection argument.
A
While no Colorado court has directly decided this question, it has been considered by the courts of many other states. “The law is well established that, where a state constitution provides for certain officials and names the qualification for such officers, the legislature is without authority to prescribe additional qualifications.” State v. Welch, 198 Or. 670, 259 P.2d 112, 114 (1953). See also Whitney v. Bolin, 85 Ariz. 44, 330 P.2d 1003 (1958); Thomas v. State, 58 So.2d 173 (Fla.1952); People v. McCormick, 261 Ill. 413, 103 N.E. 1053 (1913); State ex rel. Palagi v. Regan, 113 Mont. 343, 126 P.2d 818 (1942); Gibbany v. Ford, 29 N.M. 621, 225 P. 577 (1924); Cornell v. McAlister, 121 Okla. 285, 249 P. 959 (1926); State v. Betensen, 14 Utah 2d 121, 378 P.2d 669 (1963); C.T. Foster, Annotation, Legislative Power to Prescribe Qualifications for or Consideration of Eligi*1207bility to Constitutional Offices, 34 A.L.R.2d 155, 171 (1965) (hereinafter referred to as Legislative Power to Prescribe Qualifications ); 63A Am.Jur.2d, Public Officers and Employees § 37 (1984) (“The general rule is that where the Constitution establishes specific eligibility requirements for a particular constitutional office, the constitutional criteria are exclusive.”).
The rationale for the rule is expressed by the maxim, “expressio unius est exclusio al-terius” — the expression of one thing is the exclusion of another. Cornell, 249 P. at 960.
The qualifications fixed in the Constitution are exclusive for the reason that if it were not intended by the framers thereof to fix all the qualifications, then it must have been intended to fix only a part and leave it to the legislature to fix others. Such a view is inconsistent with accepted constitutional construction that the enumeration of certain specified things in a. Constitution will usually be construed to exclude all other things not so enumerated.
Whitney, 330 P.2d at 1005.
While the text of the constitution, rules of constitutional construction, and the precedents of this court all support the adoption of the majority rule, see infra pp. 1208, it is important to recognize that this rule is grounded, ultimately, on unassailable principles of democratic governance. If the qualifications set out in Article XIV, section 10 for the office of county assessor can only be read as establishing a minimum requirement, and not as a limitation on the imposition of additional qualifications by the General Assembly then there can be no doubt that the General Assembly would have the power to add qualifications for other constitutional offices.4 For example, the legislature could require that a governor obtain a degree in government by completing a prescribed course in an accredited university within one year after taking office, or that a justice take courses in jurisprudence for certification within a certain time frame. The legislature could also make obtaining a certificate by completing a minimum number of hours of classroom instruction and passing a standardized legislator’s examination within six months after taking office a requisite for representatives and senators.5
As such, the most fundamental right reserved to the people — the right to vote for *1208representatives of their choice—-would hinge not on constitutional guarantees, but on the General Assembly’s willingness to abstain from imposing additional qualifications for holding constitutional offices.
[I]f the legislature possesses the power to vary the constitutional qualifications for office by adding new requirements or imposing additional limitations, then eligibility to office and freedom of elections depend, not upon constitutional guarantees, but upon legislative forbearance. If the legislature may alter the constitutional requirements, its power is then unlimited, and only such person may be elected to office as the legislature may permit.... [W]hen the Constitution undertakes to prescribe qualifications for office, its declaration is conclusive of the whole matter, whether in affirmative or negative form.
McCormick, 103 N.E. at 1057.
In a constitutional democracy the principle that the people must be permitted to vote for candidates of their choosing and in conformity with constitutional mandates is beyond question. Indeed, this principle is one of the primary features which distinguishes a constitutional democracy from other forms of government. That the right of the people to choose their representatives could hinge not on constitutional guarantees but on the predilections of the legislature, no matter how well-intentioned, is contrary to this elemental postulate of democratic government.
B
Keeping this justification for the majority rule in mind, we turn to the provisions of the Colorado Constitution. See Legislative Power to Prescribe Qualifications at 155 (“the question of whether a given state legislature has power to prescribe eligibility qualifications for a constitutional office depends, essentially, upon the relevant content of the state constitution”).
The Colorado Constitution, unlike the federal constitution, does not comprise a grant of but rather, a limitation on power. All power which is not limited by the constitution is vested in the people and may be exercised by them via their elected representatives so long as the constitution contains no prohibition against it. Colorado State Civil Serv. Employee Ass’n v. Love, 167 Colo. 436, 448 P.2d 624 (1968). This principle supports the conclusion that the legislature does not have the power to impose additional qualifications for holding the office of county assessor.
Article XIV, section 10 requires only that a person be a qualified elector and have resided in the county one year prior to the election. The fact that the framers of the state constitution chose to specify the qualifications for this office limits, by implication, the legislature’s power to impose additional qualifications. See Thomas v. State, 58 So.2d 173, 177 (Fla.1952). Recognizing that the Colorado Constitution is a limitation on the power of the legislative branch supports, rather than contradicts, the conclusion that the General Assembly does not have the power to impose additional qualifications for holding the office of county assessor.
Second, it is significant to note that of the many constitutional provisions prescribing qualifications for constitutional offices, only those for county judges, school superintendents, and county attorneys specifically provide that the legislature has discretion to establish additional qualifications for those offices. Colo. Const. art. VI, § 16; Colo. Const. art. IX, § 6; Colo. Const. art. XIV, § 8. To conclude that the legislature’s plenary power vests it with the ability to add qualifications for all constitutionally created offices would render the above provisions redundant. Because we presume that each phrase of the constitution was included for a purpose, Colorado State Civil Serv. Employee Ass’n v. Love, 167 Colo. 436, 447, 448 P.2d 624, 628 (1968), the most reasonable conclusion to be drawn from these provisions is that the constitution only authorizes legislatively adopted qualifications where specifically allowed.
Third, we conclude that our precedent, rather than conflicting with the majority rule as the Board argues, actually supports it. For instance, in Yenter v. Baker, 126 Colo. 232, 248 P.2d 311 (1952), we considered whether a statute that provided that initia*1209tive petitions must be filed “at least eight months” before election violated article V of the Colorado Constitution, which provided that such petitions must be filed “at least four months” before the election. The plaintiff in Yenter argued that the four month constitutional requirement did not establish a minimum requirement which would always permit filing any time not less than four months prior to the election, but permitted the legislature to increase the minimum time requirement beyond the constitutionally mandated minimum.
In holding that where “the Constitution ... sets a limitation, the legislature may not make any other limitation than those provided in the Constitution,” id. at 241, 248 P.2d at 816, we relied on People v. McCormick, 261 Ill. 413, 103 N.E. 1053 (1913). In McCormick, the Illinois Supreme Court considered whether the legislature could increase the residency requirements beyond that set forth in the Illinois Constitution, which provided that no person shall be elected to any office “who shall not have resided in this state one year next preceding the election.” Id. 103 N.E. at 1056. The court ruled that, where the constitution declares the qualifications for office, they are exclusive and it is not within the power of the legislature to change or add to them. Id. The holding of Yenter supports the general rule that constitutionally imposed requirements for holding constitutional offices are exclusive.6
Thus, we conclude that the qualifications for the office of county assessor are fixed by the constitution and that the imposition of additional qualifications by the General Assembly is prohibited.
C
We reject the rule adopted by some courts which have held that negatively phrased qualifications for specific offices do not imply that those qualifications are exclusive, but set only minimum requirements that may be supplemented by the legislature. See, e.g., Boughton v. Price, 70 Idaho 243, 215 P.2d 286 (1950). In our judgment, to embrace the rule of Boughton requires rejection of the “accepted [principle of] constitutional construction that the enumeration of certain specified things in a constitution will usually be construed to exclude all other things not so enumerated.” Whitney v. Bolin, 85 Ariz. 44, 330 P.2d 1003, 1005 (1958). See also 1 J. Story, Commentaries on the Constitution of the United States § 625, 461 (1891) (“It would seem but fair reasoning, upon the plainest principles of interpretation, that-when the Constitution established certain qualifications as necessary for office, it meant to exclude all others as prerequisites.”). The rationale for this rule was well stated by the Arkansas Supreme Court:
The qualifications fixed by the constitution to be county judge in this state inferentially prohibit the legislature from fixing additional qualifications. Why fix them in the first place if the makers of the constitution did not intend to fix all the qualifications required, and why fix only a part of them and leave it to the legislature to fix other qualifications? There is no reasonable answer to these questions. The makers of the constitution knew exactly what qualifications a county judge should have and fixed them, and of course, fixed all of them and not a part of them. The makers of the constitution intended to cover the whole subject of the qualifications for a county judge. Had the makers of the constitution intended otherwise they would have created the office of the county judge with direction to the legislature to fix their qualifications.
*1210Mississippi County v. Green, 200 Ark. 204, 138 S.W.2d 377, 379 (1940).
This reasoning is particularly persuasive as applied to the Colorado Constitution given the fact that the framers did express their intent to permit the legislature to fix additional qualifications for certain offices, but declined to so provide for the office of county assessor. See supra pp. 1208-1209.7 Consequently, we conclude that the negative phrasing of article XIV, section 10 is immaterial to determining whether the qualifications contained therein are exclusive. See, e.g., Whitney, 330 P.2d at 1005 (“We conclude that any distinction between the statement of the constitutional qualification in the negative as opposed to the affirmative is so tenuous that there is no reasonable basis for its existence.”); Chambers v. Terry, 40 Cal.App.2d 153, 104 P.2d 663, 666 (1940) (negative phrasing immaterial to whether provision sets forth exclusive qualifications for constitutional office); McCormick, 103 N.E. at 1057 (same). See also State v. Welch, 198 Or. 670, 259 P.2d 112, 115 (1953) (rejecting the rule of Boughton and concluding that all of the cases applying that rule were inapposite because they either involved offices that were not created by the constitution or involved constitutional offices for which no qualifications were prescribed).8
The Board, while conceding that the weight of authority is in accordance with the majority rule, argues that for a number of reasons Colorado should reject that rule. First, it contends the rule that general requirements set forth in the constitution are not exclusive for holding a constitutionally created office is supported by the precedent of this court. In support of this contention, the Board cites Darrow v. People, 8 Colo. 417, 8 P. 661 (1885). In Darrow, the plaintiff argued that he was unlawfully disqualified from holding the office of alderman of the city of Denver. His disqualification was based on his failure to pay taxes in Denver during the year prior to his election — a requirement imposed by the legislature as a prerequisite to holding the office of city alderman.
Darrow is clearly distinguishable from the present case because the office of alderman is a legislatively, not constitutionally created office. Id. at 421, 8 P. at 664. This distinction is critical because, as a general rule, a legislative body has expansive power over offices created by it:
There is a distinction between offices created by the Constitution and those created by statute. Where an office is created by statute, it is wholly within the power of the Legislature creating it. The length of term and mode of appointment may be altered at pleasure, and the office may be abolished altogether.... It is not so of constitutional offices.
McCormick, 103 N.E. at 1057. See also Legislative Power to Prescribe Qualifications at 168. Darrow is not controlling here.
The Board also argues that the settled practice of the General Assembly indicates *1211that the constitutional requirements are not exclusive. It points out that numerous requirements for office have been imposed by the legislature on other constitutionally created offices. The short response to this argument is, of course, that prior unconstitutional enactments do not justify later ones.
Giving the argument more credit than perhaps it is due, it is significant to note that most of the requirements cited by the Board are not analogous to those at issue here. To the contrary, the majority of the requirements cited to by the Board are bond and oath requirements. Bond and oath requirements traditionally are not considered qualifications for eligibility to office, but rather requirements necessary to “qualify” to take office under provisions such as article XII, section 10 of the Colorado Constitution. See, e.g., State v. Ellis, 110 Mont. 43, 98 P.2d 879, 881-82 (1940) (“To ‘qualify means to file an official bond and oath_ [T]he qualifications which must ... be present at the time of election, are limited to age and residence”); Legislative Power to Prescribe Qualifications at 162 (qualifications “are primarily those laid down as prerequisites to election or appointment to a constitutional office, and may generally be distinguished from requirements relating to ‘qualifications’ to serve in an office to which one has been elected or appointed, such as a requirement that an electee or appointee must ‘qualify by giving a certain bond or by taking an oath of office”).
Consequently, we conclude that none of the reasons advanced by the Board are persuasive.
Ill
The Colorado Constitution reserves no authority in the state legislature to change, add to, or diminish the qualifications for constitutionally created offices. Accordingly, we hold that the licensing requirements of the Act as applied to county assessors are unconstitutional and that Reale cannot be enjoined from holding the office of Adams County Assessor.
The judgment is reversed and the case remanded to the trial court with directions to dismiss the complaint.
. The terms "appraiser” and "assessor” are not synonymous. "Assessor” refers to an elected constitutional officer who performs the statutory and other duties of the office of assessor, while *1206"appraiser” refers to one who estimates the value of real property for a fee or a salary. See § 12-61-702(5), 5B C.R.S. (1994 Supp.).
. The stated purpose in imposing the licensing requirement is to meet the standard imposed by the federal Financial Institutions Reform, Recovery, and Enforcement Act of 1989. § 12-61-701, 5B C.R.S. (1991). The federal legislation requires that real estate appraisals "utilized in connection with federally related transactions are performed ... by individuals whose competency has been demonstrated.” 12 U.S.C. § 3331 (1994 Supp.). County assessors are not involved in "federally related transactions.”
. Reale sought review of the trial court's order by filing a petition for an original proceeding or, in the alternative, a writ of certiorari and motion to stay with this court. We granted Reale’s petition for writ of certiorari pursuant to C.A.R. 50 and issued a stay.
. The language employed by the framers of the Colorado Constitution to state the requisite qualifications for other constitutional offices precisely mirrors that used in article XIV, section 10 for the position of county assessor.
Colo. Const, art. VI, § 8 provides for the qualifications of justices and states, "[n]o person shall be eligible to the office of justice of the supreme court unless he shall_" Likewise, in describing the qualifications for district judges, Colo. Const, art. VI, § 11 provides “[n]o person shall be eligible to the office of district judge unless he shall_" The qualifications enunciated for district judges similarly apply to both probate judges and juvenile judges. Colo. Const, art. VI, §§ 14-15.
Qualifications for the positions of governor and attorney general are stated in Colo. Const, art. IV, § 4 which provides "[n]o person shall be eligible to the office of governor ... unless he shall ... nor to the office of attorney general unless he shall....”
Similarly, Colo. Const, art. V, § 4, relating the qualifications for legislators states "[n]o person shall be a representative or senator who shall not have
. Granting the legislative branch the unchecked ability to prescribe qualifications for elected constitutional officers tips the delicate balance of powers which underlies our constitution. Article III of the Colorado Constitution provides "[t]he powers of the government of this state are divided into three distinct departments, — the legislative, executive and judicial; and no person or collection of persons charged with the exercise of powers properly belonging to one of these departments shall exercise any power properly belonging to either of the others, except as in this constitution expressly directed or permitted.” This court has stated "[t]he fundamental meaning of the separation of powers doctrine is that the three branches of government are separate, coordinate, and equal.... [and] 'these principles, concepts, and doctrines are so thoroughly embedded in our legal system that they have become bone and sinew of our state and national polity.'" Pena v. District Court, 681 P.2d 953, 956-57 (Colo.1984) (emphasis added) (quoting Smith v. Miller, 153 Colo. 35, 40-41, 384 P.2d 738, 741 (1963)). See also People ex rel. Walker v. Capp, 61 Colo. 396, 158 P. 143 (1916) (explaining when the constitution creates an office or provides that the Governor appoint an executive official "it may be conceded that the Governor’s discretion could not be interfered with by the legislature.") Id. at 398, 158 P. at 144. We cannot subscribe to a legislative practice that allows one branch of the government to limit constitutionally established "executive” offices and thus to do indirectly that which they are prohibited from doing directly.
. In addition, we note that in 1981, Colorado Attorney General J.D. MacFarlane issued an opinion as to whether the legislature could add qualifications for the constitutionally created office of county coroner. The Attorney General concluded that the legislature could not impose additional requirements on the office based on the majority rule: "Because the office of county coroner is created by the Constitution and qualifications for holding office are specified in the Constitution, it is my opinion that the legislature cannot add to those qualifications by adopting experience and training requirements for that office.” Op.Atty.Gen. No. CAG/AGA/AGAFP/MIC (Feb. 9, 1981). The qualifications cited in the Attorney General’s opinion are the same qualifications applicable to county assessors. See Colo. Const, art. XIV, § 10. The Attorney General’s opinion that the majority rule applies to offices created by the Colorado Constitution supports our view. See Colorado Ass'n of Public Employees v. Lamm, 677 P.2d 1350, 1360 (Colo.1984).
. This conclusion also finds support in the proceedings of the constitutional convention. After the work of the Colorado Constitutional convention was completed, a committee of that body was appointed to prepare an address to the people, informing them of the main features of the instrument framed for their adoption or rejection. In Re: Lowrie, 8 Colo. 499, 9 P. 489 (1885). The address is an authentic memorial of the time. People v. May, 9 Colo. 80, 10 P. 641 (1885). With regard to eligibility to hold state and county offices, the address stated: "We have declared that all persons who are qualified electors at the adoption of the Constitution, shall be eligible to the several state offices, to the general assembly, and to the various county offices." Address to the People, Proceedings of the Constitutional Convention, 1875-1876, p. 731 (1907). In our opinion, this declaration supports the contention that the framers placed no signifi-canee on the negative phrasing of art. XIV, § 10. The characterization of that section is itself in positive form and unconditionally extends eligibility to office to all qualified electors.
. As previously described in footnote four, the language employed by the framers to state the requisite qualifications for other constitutional offices precisely mirrors that used in article XIV, section 10 for the position of county assessor.
Thus, if negative phrasing is dispositive of the authority of the legislature to prescribe additional qualifications for county assessor, its power would extend to qualifications for governor, judicial offices and the legislature itself. The legislature would effectively control who could hold these offices, dramatically curtailing the most fundamental right reserved to the people, the right to have persons they elect remain in office.