dissenting. The sole issue before this court is whether, in the absence of blood alcohol evidence, operation of a motor vehicle while impaired by liquor, in violation of General Statutes (Rev. to 1985) § 14-227a (b), is a lesser included offense of operation under the influence of liquor, in violation of General Statutes (Rev. to 1985) § 14-227a (a). The majority opinion holds that since the operation while impaired statute, “by its very terms, provides that one commits the offense only when one’s blood alcohol ratio falls between .07 and .1 percent,” it cannot be a lesser included offense of operation under the influence of liquor. (Emphasis added.) I disagree with that conclusion.
The arrest of the defendant occurred on June 21, 1985. The statutes relating to driving after drinking have been undergoing progressive development in recent years. For that reason, we must confine our analysis of the question before us to the law in effect on the date of the offense. General Statutes (Rev. to 1985) § 14-227a (b) provided: “No person shall operate a motor vehicle . . . while his ability to operate such motor vehicle is impaired by the consumption of *225intoxicating liquor. A person shall be deemed impaired when at the time of the alleged offense the ratio of alcohol in the blood of such person was more than seven-hundredths of one per cent of alcohol, by weight, but less than ten-hundredths of one per cent of alcohol, by weight.”
In determining the true meaning of a statute when there is genuine uncertainty as to how it should apply, identifying the problem in society to which the legislature addressed itself by examining the legislative history of the statute under litigation is helpful. State v. Gaines, 196 Conn. 395, 400, 493 A.2d 209 (1985); State v. Belton, 190 Conn. 496, 505-506, 461 A.2d 973 (1983); State v. Campbell, 180 Conn. 557, 562, 429 A.2d 960 (1980).
General Statutes (Rev. to 1985) § 14-227a (b) had its genesis in the 1983 legislative session as Substitute House Bill No. 6420. This bill, as reported favorably by the committee on the judiciary, was entitled “An Act Concerning the Penalties for Drunk Driving.” It created three degrees of the offense of operating a motor vehicle under the influence of liquor, with proportionate penalties, and varying with a person’s blood alcohol percentage as follows: first degree — .2 percent or more; second degree — .15 percent or more, but less than .2 percent; third degree — .1 percent or more, but less than .15 percent. The bill also created a fourth offense as follows: “A person is guilty of operating a motor vehicle while impaired when the evidence establishes that such person was operating a motor vehicle and at the time of the alleged offense the ratio of alcohol in the blood of such person was five-hundredths of one per cent or more of alcohol, by weight, but less than ten-hundredths of one per cent of alcohol, by weight, and additional competent evidence is presented indicating that at the time of the alleged offense the ability of such person to operate the motor vehicle was *226impaired by the consumption of intoxicating liquor.” (Emphasis added.) The penalty provided was a fine of not more than five hundred dollars.
Other relevant new provisions were as follows: Evidence that the defendant refused to submit to a blood, breath or urine test requested under the law was admissible in any criminal prosecution for operation under the influence of liquor or while impaired by liquor. If any person, after being arrested for driving while impaired by the consumption of liquor, refused to submit to a blood alcohol test, the arresting officer was required to revoke his operator’s license immediately for twenty-four hours. A sworn report to the commissioner of motor vehicles must then be made setting forth “the grounds for the officer’s belief that there was probable cause to arrest such person for operating a motor vehicle . . . while his ability to operate such motor vehicle is impaired by the consumption of intoxicating liquor . . . .” Thereafter, a suspension of license for ninety days followed, subject to an immediate administrative hearing to determine, inter alia, the existence of probable cause for the arrest. A subsequent refusal of a blood alcohol test called for a further sworn report of probable cause to arrest, and a similar hearing after suspension of the operator’s license.
The first consideration of the proposed legislation took place in the House of Representatives. During the debate, several amendments were adopted to give the bill its final form as Public Acts 1983, No. 83-534, of which General Statutes (Rev. to 1985) § 14-227a (b) was an integral part. House amendment schedule “A” was the most comprehensive. By this amendment, the proposed three degrees of operation under the influence of liquor were abolished. Instead, the amendment provided for increased penalties upon conviction for first and subsequent offenses.
*227The most important change was the adoption of what later became General Statutes (Rev. to 1985) § 14-227a (b). For the per se violation of operation under impairment, the threshold blood alcohol level was increased from .05 to more than .07 percent, and its criminal classification was reduced from a misdemeanor to an infraction. The judiciary committee’s proposal requiring additional evidence of impaired driving was removed in amendment schedule “A.” Evidence of a refusal to submit to a blood alcohol test was now admissible in the criminal prosecution of operation under the influence only. Continued in this amendment were the provisions that the officer make a sworn report to the commissioner of motor vehicles of his grounds to believe probable cause existed to make the arrest, and for proof of such probable cause at the subsequent suspension hearing. Such report and proof were also required upon a subsequent refusal to submit to a blood alcohol test.
The only remarks on the floor during the consideration of this amendment were these of Representative Christopher Shays: “It establishes a new offense called impairment. If someone’s blood alcohol content is between .07 and below .10, that is an offense, an infraction.” 26 H.R. Proc., Pt. 19, 1983 Sess., p. 6676.
Of significance in this legislative review is the adoption of house amendment schedule “D.” This was a further amendment to schedule “A” adopted earlier and provided in relevant part as follows: “In any criminal prosecution for a violation of [operation under the influence of liquor or operation while impaired], evidence that the defendant refused to submit to a blood, breath or urine test requested in accordance with section 14-227b shall be admissible provided the requirements of subsection (b) of said section have been satisfied.” (Emphasis added.) The legislative proceedings contain no explanation for the extension to prosecutions for *228operation while impaired of this evidential rule, originally included in the committee bill, but previously excluded by amendment schedule “A.”
Also relevant to our analysis of this legislative history of § 14-227a (b) is house amendment schedule “G,” which was rejected by that body. This amendment sought to establish a “per se” violation standard for operating a motor vehicle under the influence of intoxicating liquor “while the ratio of alcohol in the blood of such person is ten-hundredths of one per cent or more of alcohol, by weight.”1 During the debate on this proposal, Representative Robert Farr made these remarks: “[I]n the bill in chief, we in fact have established a per se law. The bill in chief says that .07 to or below .1 is per se, a violation. And that’s all we are doing here is establishing .1 or above as a violation.” 26 H.R. Proc., Pt. 19, 1983 Sess., p. 6850.
Further relevant to our legislative review is house amendment schedule “L,” which failed of adoption. This amendment proposed to limit the definition of driving while impaired by restoring the two-fold requirement of proof originally proposed in the committee bill, but rejected by amendment schedule “A.” It provided as follows: “A person is guilty of operating a motor vehicle while impaired when the evidence establishes that such person was operating a motor vehicle and at the time of the alleged offense the ratio of alcohol in the blood of such person was more than eight-hundredths of one per cent of alcohol, by weight, but less than ten-hundredths of one per cent of alcohol, by weight, and additional competent evidence is presented indicating that at the time of the alleged offense the *229ability of such person to operate the motor vehicle was impaired by the consumption of intoxicating liquor.” (Emphasis added.)
Upon receipt of Substitute House Bill No. 6420, as amended by the House of Representatives, the Senate adopted a further amendment not relevant to driving while impaired. In the debate on approval of the bill with all amendments, Senator Howard T. Owens, Jr., made the following explanatory remarks: “It establishes a new offense of driving while impaired, blood alcohol content of above .07 or below .10 and imposes a penalty of an infraction. I can say that the original plan was to make that a criminal misdemeanor. I thought and someone had talked about a .05 to a .10 level and I thought that could be two or three beers and maybe that’s not what we were trying to come at and to not make it where they have a criminal penalty, .07 to below .10 is obviously impaired but does not reach the test by any expert’s opinion of being under the influence or being intoxicated.” 26 S. Proc., Pt. 13, 1983 Sess., p. 4424. As amended by the Senate, the bill was finally approved by the House of Representatives on June 7, 1983. Upon signing by the Governor, the bill became Public Acts 1983, No. 83-534.
The precise question raised by this appeal is one of first impresssion in this state. It is helpful, therefore, to examine the particular statute in effect, its language and its legislative development. See Penfield v. Jarvis, 175 Conn. 463, 466, 399 A.2d 1280 (1978). In construing statutes, courts consider their legislative history, their language, their purpose, and the circumstances surrounding their enactment. We look to the history of the law, its language, considered in all its parts, the mischief the law was designed to remedy, and the policy underlying it. Kellems v. Brown, 163 Conn. 478, 505-506, 313 A.2d 53 (1972), appeal dismissed, 409 U.S. 1099, 93 S. Ct. 911, 34 L. Ed. 2d 678 (1973).
*230The cardinal rule is that statutes are to be construed so as to carry out the expressed intent of the legislature. While the intent of the statute must be ascertained from the language used if it is clear and unambiguous, where the language is of doubtful meaning, the statute is to be construed in the light of all of its provisions, the object which it seeks to accomplish and all other relevant circumstances. Jarvis Acres, Inc. v. Zoning Commission, 163 Conn. 41, 46, 301 A.2d 244 (1972); Anderson v. Ludgin, 175 Conn. 545, 552, 400 A.2d 712 (1978). The debate surrounding passage of a law may be an aid to statutory construction if it sheds light on the legislature’s purpose. The title and stated purpose of the legislation are also valid aids to construction. Anderson v. Ludgin, supra, 545. No word in a statute should be treated as superfluous or insignificant. Kulis v. Moll, 172 Conn. 104, 111, 374 A.2d 133 (1976). No part of a legislative enactment is to be treated as insignificant or unnecessary, and there is a presumption of purpose behind every sentence, clause or phrase in a statute. Winchester v. Connecticut State Board of Labor Relations, 175 Conn. 349, 355-56, 402 A.2d 332 (1978). Insofar as it is possible, the entire enactment is to be harmonized, each part made operative. State v. Grant, 176 Conn. 17, 20, 404 A.2d 873 (1978).
Applying these principles of statutory construction to the enactment of Public Acts 1983, No. 83-534, I reach the conclusion that in the absence of blood alcohol evidence, operation of a motor vehicle while impaired by liquor, in violation of General Statutes (Rev. to 1985) § 14-227a (b), is a lesser included offense of operation under the influence, in violation of § 14-227a (a).
Substitute House Bill No. 6420 was reported favorably by the judiciary committee for adoption by the legislature. Its purpose was defined in its title, “An Act Concerning the Penalties for Drunk Driving.” House Bill No. 6420, upon its introduction, contained no pro*231vision for driving while impaired when it was originally referred to the judiciary committee. That section was first inserted by the committee in the substitute bill that it reported favorably for passage.
The substitute bill originally restructured the offense of “drunk driving” into four degrees, carrying proportionate penalties, and varying numerically with a person’s decreasing blood alcohol percentage in this sequence: first degree — .2 percent or more; second degree — .15 percent or more, but less than .2 percent; third degree — .1 percent or more, but less than .15 percent. The “fourth degree,” however, was not so called. Because it classified an offense relating to a blood alcohol percentage of under .1 percent, which is generally considered to be the blood alcohol level needed for the offense of driving under the influence of liquor, the “fourth offense or degree of drunk driving” was designated as “operating a motor vehicle while impaired.” This offense was to apply when the blood alcohol ratio fell between .05 percent or more, but less than .1 percent “and additional competent evidence is presented indicating that at the time of the alleged offense the ability of such person to operate the motor vehicle was impaired by the consumption of intoxicating liquor.” (Emphasis added.) The new offense was a misdemeanor carrying a maximum fine of five hundred dollars.
As initially proposed by the judiciary committee, conviction for operation while impaired required the stated amount of blood alcohol plus other evidence of impaired driving. House amendment schedule “A” eliminated the three degrees of operation under the influence of liquor and redefined the new offense of driving while impaired by removing the second requirement of “additional competent evidence” of impaired driving.
Section 1 (a) reverted to the then existing offense of operation of a motor vehicle “while under the influence *232of intoxicating liquor or any drug or both.” The offense continued not to be further defined. Subsection (b) provided that no person shall operate a motor vehicle “while his ability to operate such motor vehicle is impaired by the consumption of intoxicating liquor.” Such “impaired driving,” like “driving under the influence,” was not defined, except that a “per se” violation was contained in the provision that “[a] person shall be deemed impaired when at the time of the alleged offense the ratio of alcohol in the blood of such person was more than seven-hundredths of one per cent of alcohol, by weight, but less than ten-hundredths of one per cent of alcohol, by weight.”
I disagree with the majority opinion in its conclusion that this “per se” standard is the only manner in which the offense may be committed. The specified prohibition was against driving while one’s ability to operate was impaired by the consumption of intoxicating liquor, and not just against driving with a blood alcohol percentage above .07 and below .1 percent, which is merely one manner of violating the statute, now made an infraction. That was the thrust of the legislation. That was the intent of the legislature.
Other provisions of amendment schedule “A” written into Public Acts 1983, No. 83-534, confirm my conclusion of error below. Evidence of a blood alcohol test was admissible under certain conditions as follows: (1) a reading above .05, but less than .1, percent could be considered with other evidence in determining operation under the influence of liquor; (2) a reading above .07, but less than .1, percent “shall constitute impairment within the meaning of this section”; (3) a ratio of .1 percent or more of alcohol “shall be prima facie evidence that the defendant was under the influence of intoxicating liquor within the meaning of this section.”
*233Section 2 of schedule “A” amended the implied consent to blood test law. General Statutes (Rev. to 1985) § 14-227b. It now applied to an arrest for driving while impaired by the consumption of liquor. In the event of a test refusal, the police officer was required to make a sworn report setting forth “the grounds for the officer’s belief that there was probable cause to arrest such person for operating a motor vehicle . . . while his ability to operate such motor vehicle is impaired by the consumption of intoxicating liquor . . . .’’(Emphasis added.) The administrative hearing thereafter, relative to the suspension of a license for such test refusal, required a determination, inter alia, of whether “the police officer [had] probable cause to arrest the person for operating a motor vehicle . . . while his ability to operate such motor vehicle [was] impaired by the consumption of intoxicating liquor.” Upon a subsequent refusal of blood alcohol test, a similar report and administrative inquiry were required. Such a sworn report and administrative finding of probable cause for arrest in the event of a blood alcohol test refusal must of necessity relate to an arrest for operation while impaired based upon facts other than the proscribed blood alcohol percentages. Of similar import and conclusion is the provision adopted by house amendment schedule “D,” providing that in the event of prosecution for a violation of operation under the influence of liquor or operation while impaired, evidence of a blood alcohol test refusal was admissible.
The only logical conclusion to be drawn from this legislative history is that a violation of the impaired driving statute, while provable per se by an operator’s blood alcohol ratio of more than .07, but less than .1, percent, may be established by other competent evidence in the same manner as a violation of operation under the influence of intoxicating liquor may be proven without a blood alcohol report. The interrelationship *234of the various amendments adopted by the legislature and incorporated into the final bill show a harmony of purpose and design to extend the scope of “drunk driving” offenses, but to a lesser degree ofproof and punishment, to driving while one’s ability to operate a motor vehicle is impaired by the consumption of intoxicating liquor, whether provable by a blood alcohol test or by other competent evidence.
The operation of a motor vehicle while under the influence of intoxicating liquor within the prohibition of General Statutes § 14-227a (a) “has been construed to require ‘that a driver had become so affected in his mental, physical or nervous processes that he lacked to an appreciable degree the ability to function properly in relation to the operation of his vehicle.’ Infeld v. Sullivan, 151 Conn. 506, 509, 199 A.2d 693 [1964].” Higgins v. Champ, 161 Conn. 200, 203, 286 A.2d 313 (1971); see State v. Hancich, 200 Conn. 615, 622, 513 A.2d 638 (1986). Driving while one’s ability to operate is impaired by the consumption of intoxicating liquor has not been defined, except for the statutory per se violation by a blood alcohol ratio of more than .07, but less than .1, percent of alcohol, by weight. State v. Hancich, supra, 620. Our courts have not had occasion before this case to define the full meaning of driving while one’s ability to operate is impaired by the consumption of intoxicating liquor.
Section 14-227a (b) prohibiting the operation of a motor vehicle while impaired by the consumption of intoxicating liquor is a unique law. A related statute, however, is found in Michigan Statutes Annotated § 9.2325 (2), which provides: A person shall not “operate a vehicle . . . when, due to consumption of intoxicating liquor . . . he has visibly impaired his ability to operate the vehicle. Where a person is charged with [driving while under the influence of intoxicating *235liquor], a finding of guilty shall be permissible under this section.” The Michigan Supreme Court has approved the following charge to express the legislative intent necessary for a conviction under its impaired driving law: “ ‘The distinction between the crime of driving under the influence of intoxicating liquor and the lesser included offense of driving while ability is visibly impaired is the degree of intoxication which the people must prove. To prove driving under the influence of intoxicating liquor, the people must prove that defendant’s ability to drive was substantially and materially affected by consumption of intoxicating liquor. To prove driving while ability is visibly impaired, the people must prove that defendant’s ability to drive was so weakened or reduced by consumption of intoxicating liquor that defendant drove with less ability than would an ordinary, careful and prudent driver. Such weakening or reduction of ability to drive must be visible to an ordinary, observant person.’ ” People v. Lambert, 395 Mich. 296, 305, 235 N.W.2d 338 (1975).
For the above reasons, I would find that in the absence of blood alcohol evidence, the operation of a motor vehicle by a person while his ability to operate such motor vehicle is impaired by the consumption of intoxicating liquor, in violation of General Statutes (Rev. to 1985) § 14-227a (b), is a lesser included offense of operation under the influence of liquor, in violation of General Statutes (Rev. to 1985) § 14-227a (a).
Accordingly, I would find error.
Such a “per se” violation of operating a motor vehicle while under the influence of intoxicating liquor was adopted in 1985 by Public Acts 1985, No. 85-596, § 1.