Petition for Rehearing
*91WARNER, J.Upon petition of the defendant school district a rehearing was granted. It was predicated upon the proposition that the court erred in the original opinion in construing the Teachers’ Tenure Law (ORS 342.205 to 342.330) in such a way as to create a class of regular teachers, neither “permanent” nor “probationary”, who would attain tenure status automatically at the end of their third year of employment.
To sustain this contention the school district advanced a thesis so casually and indifferently presented in its first brief, and never exploited in its initial oral argument, that we may appropriately say that it now comes to us in the form of a first presenta^ tion. Its persuasive force is materially aided by the respondent’s forthright acceptance of our holding that the word “or”, appearing in the statute, is there used in its literal and disjunctive sense rather than in a conjunctive character, as so earnestly urged in the school district’s first brief and thereafter contended for with equal zeal at the first oral presentation. Had not counsel’s first argument so depended upon our acceptance of the meaning which he then assigned to the word “or”, we doubt if this petition for rehearing would have been necessary. We are indebted to both appellant and respondent for the comprehensive briefs now furnished and their able arguments made at the last hearing.
The respondent now contends that the phrase in the first clause of § 111-2304, OCLA (ORS 342.210) reading, “have been regularly appointed and employed * * * for not less than three successive school years” indicates that this clause was intended to oper*92ate retrospectively and not prospectively, as argued by tbe appellant.
To fully appreciate tbe legislative intent and meaning encompassed in § 111-2304, we are compelled to give consideration to the entire act of 1935 (Oregon Laws 1935, ch 125). This persuades us that the proper construction of the first clause of the second sentence of § 4—a construction which avoids the objections and anomalies which, as we later point out, result from the court’s original decision, and which makes a harmonious whole of all the separate provisions of the statute—is that it was intended to apply retroactively to teachers who, before the effective date of the new act, had been regularly appointed and employed for not less than three successive school years. This meaning clearly appears when the whole sentence is read: “ ‘Permanent’ teacher or teachers shall mean and include all teachers who have been regularly appointed and employed by any such school district for not less than three successive school years, or who may hereafter be placed upon the permanent list by resolutions of the school board as hereinafter provided.” (Italics ours.) The change from past tense in the first clause to future tense in the second clearly indicates that, while the seeond clause refers to something that will occur after the effective date of the act, the first clause refers to something that has already occurred.
The 1935 act repealed the prior law and wiped out tenures acquired under it. Campbell v. Aldrich, 159 Or 208, 79 P2d 257; cases collected in 147 ALR at p. 299. The evident purpose was to give the same benefits to teachers who had previously served three years as to those who should thereafter serve for three years, omitting, however, the requirement of a resolution *93of the board of directors. This would be by way of compensation for the loss of rights previously acquired.
The first teachers’ tenure act was passed in 1913. General Laws of Oregon 1913, ch 37. It applied to school districts having a population of 20,000 or more persons. Section 3 provided that teachers “during their first two years of service shall be classed as probationary teachers” and authorized the board of directors to dismiss a teacher at any time during the probationary period “upon cause deemed sufficient by the board”. Section 4 provided: “Teachers who have been employed in the schools in any such district or districts as regularly appointed teachers for not less than two successive annual terms shall by the board of directors be placed upon the list of permanently employed teachers.” Teachers upon the permanent list were not subject to annual appointment but continued to serve until dismissed or discontinued by the board in the manner provided in the act.
This act was revised by General Laws of Oregon 1917, ch 152, which retained substantially the provisions of the 1913 act to which we have referred. It was again revised in 1935. Oregon Laws 1935, ch 125. The provisions of this act repeal the prior legislation and govern the present controversy. Two subsequent amendments are not pertinent to the question under consideration. See Oregon Laws 1939, ch 113; Oregon Laws 1945, ch 137. The act is found in OCLA, Title 111, ch 23, and ORS 342.210 to 342.330. In this opinion we shall refer to the 1935 act. In each instance, italics used are our own.
The title of the act reads:
“Providing the manner in which all teachers, instructors, officers, agents and/or employees of *94school districts in this state, having a population of 20,000 or more persons, shall be appointed, employed, classified, compensated, retired, dismissed, removed, discharged, transferred and/or demoted, and for the repeal of chapter XXVI, title 35, Oregon Code 1930, as amended.”
Section 3 reads:
“The board of directors of any such district shall have the power and authority to appoint, employ, and to classify and/or fix the salaries or compensation of all teachers employed, or to be employed, by said district; and in the manner hereinafter provided, and in that manner only, shall have power and authority to appoint, employ, retire, dismiss, remove, transfer and/or demote any such teacher
Section 4 reads:
“The words ‘teacher’ or ‘teachers’ when used in this act shall mean and include all supervisors, principals, vice principals and/or instructors now employed, or who hereafter may be employed, by any such school district. ‘Permanent’ teacher or teachers shall mean and include all teachers who have been regularly appointed and employed by any such school district for not less than three successive school years, or who may hereafter be placed upon the permanent list by resolutions of the school board as hereinafter provided. ‘Probationary’ teacher or teachers shall mean and include all teachers other than substitute teachers, regularly appointed and employed by any such school board during a probationary period of three successive school years, and until placed upon the permanent list as provided in section 7.”
Section 6 reads:
“Any such board shall have power and authority to discharge and/or remove any probationary *95teacher in its employ, at any time during his or her probationary period for any cause deemed sufficient by the board. Transfer or demotion of any such probationary teacher may be made at any time by the board when deemed for the good of the service; provided, however, that in the event of friction between any such teacher and his or her principal, the board shall grant said teacher the privilege of serving under another principal before taking any formal adverse action. Said board may, when it deems such action for the good of the service, refuse to renew the contract of any probationary teacher, or re-employ any such teacher when not under contract, but such teacher shall be entitled to at least ten weeks’ notice of the intended action of said board before expiration of his or her contract and/or before the end of the school year.”
Section 7 reads:
“Probationary teachers who have been employed in the schools in any such district or districts as regularly appointed teachers for not less than three successive annual terms, if retained, shall be placed by the board of directors upon the list of permanently employed teachers; provided, that any such teacher shall not be placed upon such permanently employed list until the board upon consideration of records and ratings, to be regularly and periodically made to the board, is satisfied as to qualifications and adopts a resolution transferring such teacher from the probationary list to the permanently employed list.”
Section 8 contains this provision:
“Permanent teachers shall not be subjected to the requirement of annual appointment, but shall continue to serve until retired, dismissed or discharged as provided hereinafter; provided, however, that such teachers shall at all times be sub*96jeet to temporary suspension under such reasonable rules and regulations as may be prescribed by the board.”
Section 9 has to do with the transfer of a permanent teacher from a position, in any branch of the service to another position in the same branch of the service. Section 11 contains provisions relative to recommendations by the superintendent as to the dismissal, transfer or demotion of a teacher’ and forbids dismissal of a permanent teacher except for certain specified causes. Sections 12 to 16 and § 18 prescribe the procedure for the hearing of charges against a permanent teacher. Section 20 provides for the retirement of teachers at the age of 65 years.
The 1935 act is a complete law governing the subject of the tenure of teachers in the school districts to which it is applicable. It applies to all teachers in such school districts. This appears both in the title and in the body of the act. Section 3 empowers the board to employ, classify and fix the salaries of all teachers, and authorizes the board to ‘ ‘ appoint, employ, retire, dismiss, remove, transfer and/or demote any such teacher” only in the manner thereafter provided in the act. In § 6 provisions are made for the discharge, removal and transfer or demotion of pro-: bationary teachers. Section 8 provides for the con? tinuance in service without requirement of annual appointment of permanent teachers; § 9 for the transfer ; and § 11 for the dismissal of permanent teachers. The procedural provisions of §§ 12 to 16 and § 18 all concern permanent teachers.
Since provisions of the act touching the appointment, employment, retirement, dismissal, transfer and demotion of teachers are expressly made applicable *97to all teachers of the district; and since the school board is authorized to perform these functions in the manner prescribed by the act and in no other manner; and since the act prescribes how these duties are to be discharged with respect to two classes of teachers and two only, namely, probationary and permanent, it follows that this court in its first decision adopted a construction of § 4 which is in direct conflict with the clear legislative intent, for the plaintiff, during the three years of employment upon which she relies to establish her right to permanent status, was, according to that construction, neither a probationary teacher nor a permanent teacher.
She asserts in her brief that she was not a probationary teacher within the meaning of § 7, and we agree. Of course, she could not on any theory have become a permanent teacher until she had served three successive years. Consequently, there is not a single provision of the act which could be applied to the plaintiff during this three-year period, because by express language all its provisions are made to apply either to probationary teachers or to permanent teachers, and she, we are told, was neither.
It is the duty of the court to give effect to the whole of the statute when endeavoring to determine the meaning of a particular provision and, if possible, to reconcile seemingly inconsistent provisions and bring them into harmony one with another. Anthony v. Veatch, 189 Or 462, 502, 220 P2d 493, 221 P2d 575; Portland v. Duntley, 185 Or 365, 380, 203 P2d 640; Hunter v. Cunning, 176 Or 250, 285, 154 P2d 562, 157 P2d 510; Union Pacific Railroad Co. v. Bean, 167 Or 535, 549, 119 P2d 575.
In Anthony v. Veatch, supra, Mr. Justice Hay, speaking for the court, after stating the rule that a *98court is required in the interpretation of a statute to give it such construction as will, if possible, give effect to the whole of it, quoted with approval this language from Driscoll v. Klamath County, 122 Or 515, 518, 259 P 915:
“ ‘The practical inquiry is usually what a particular provision, clause or word means. To answer it one must proceed as he would with any other composition—construe it with reference to the leading idea or purpose of the whole instrument. A statute is passed as a whole and not in parts or sections and is animated by one general purpose and intent. Consequently each part or section should be construed in connection with every other part or section and so as to produce a harmonious whole. It is not proper to confine the attention to the one section to be construed.’ ”
The following from Endlich, Interpretation of Statutes, 250, § 182, applies to this case with peculiar force:
“An author must be supposed to be consistent with himself; and, therefore, if in one place he has expressed his mind clearly, it ought to be presumed that he is still of the same mind in another place, unless it clearly appears that he has changed it.”
We quote again the second sentence of § 4 which gives rise to the controversy, italicizing some of the words: “ ‘Permanent’ teacher or teachers shall mean and include all teachers who have been regularly appointed and employed by any such school district for not less than three successive school years, or who may hereafter be placed upon the permanent list by resolutions of the school board as hereinafter provided.” If the disjunctive “or” bears its ordinary meaning and the first clause of the sentence is given prospective application, it does indeed appear to create a third class of teachers, i.e., permanent teachers who *99become such automatically after three years of service and who were never probationary teachers. The other two classes would be probationary teachers and permanent teachers who acquire permanent tenure pursuant to the provisions of § 7.
To accept this meaning of the statute introduces an element of unreasonableness, for what reason can be suggested for including in a tenure statute a class of teachers wholly unaffected by the provisions which relate to their dismissal, transfer or demotion?
The 1939 revision evinces a clear intent to tighten, rather than relax, the requirements for permanent tenure. The probationary term is increased from two to three years and a resolution of the board, based upon an examination of the teacher’s records and ratings, is required before the teacher can be transferred to the permanent list.
The plaintiff’s contention runs contrary to the basic theory of teachers’ tenure laws. The Supreme Court of Minnesota in an opinion reviewing the history of the tenure movement said, “the objectives sought have been to protect the teachers against unjust removal after having undergone an adequate probationary period.” (Italics ours.) McSherry v. City of St. Paul, 202 Minn 102, 277 NW 541. A well-documented article upon the subject in 17 Mich L Rev 430 (1938-1939), states that tenure was then in force in 19 states and the District of Columbia, and continues: “Although varying in specific details, the general pattern of these laws may be described briefly. For a period ranging from one to five years, the teacher is on probation and during that time he may be denied reemployment at the end of any school year, but dismissal during the year must be for cause.” (Italics ours.) Also see 78 CJS 1010, Schools and School Districts §180; Pro*100ceedings of the 59th Animal Meeting of the National Education Association, p. 149; Researeh Bulletin of the National Education Association, September 1936, p. 175. However, even though it were considered not unreasonable for the legislature to abolish the probationary period and to provide for permanent tenure from the beginning, it would be highly unreasonable to enact a law under which some teachers, to be selected by some unknown process, become entitled to the benefits of such a provision while others are denied them. Unless absolutely driven to it by language which admits of no other'interpretation, such an interpretation should not be adopted.
As against the construction which we think is the correct one, the general rule is invoked that statutes are to be given prospective application unless an intention to make them retroactive is clear. This court in State ex rel. Pierce v. Slusher, 119 Or 141, 150, 248 P 358, approved the following statement of the rule from Twenty Per Cent Cases, 20 Wall 187, 22 L ed 339: “ * * * courts will apply new statutes only to future cases, unless there is something in the nature of the case or in the language of the new provision which shows that they were intended to have a retroactive operation.” (Italics ours.)
Again, in Denny v. Bean, 51 Or 180, 184, 93 P 693, 94 P 503, we said:
“The rule under consideration, however, is only a guide where the intention of the legislature is obscure: Broom’s Legal Maxims, 27. If the intention of the legislature is obvious and plain, it must prevail; but if it is obscure and doubtful, it should not be given a retrospective construction, although within the wording of the act, if such construction impairs existing rights, creates new *101obligations, or imposes more duties with respect to past transactions, unless such plainly appears to be the intent of the Legislature: Sutherland, Statutory Con. § 643.”
Respecting the reason of the rule, it is said in Endlich, Interpretation of Statutes, 362, § 271: “Upon the presumption that the legislature does not intend what is unjust rests the leaning against giving certain statutes a retrospective operation.” And again at p. 367, § 273: “It is chiefly where the enactment would prejudicially affect vested rights, or the legal character of past transactions, that the rule in question prevails.”
The effect of giving a retrospective operation to the disputed language would be merely to confer a benefit which would otherwise be withheld from a class of teachers who, it may be assumed, the legislature considered had already earned the right to permanent tenure. It works no injustice and disturbs no vested rights. It not only accords with the grammatical construction of the sentence, giving due weight to a change of sense indicated by a change in language, but it removes the contradictions and inconsistencies created by the court’s construction. It is a result called for by “the nature of the case”.
The brief of the plaintiff on rehearing calls particular attention to the word “shall” in the phrase “ ‘permanent’ teacher or teachers shall mean and include” and argues that “shall” is language of the future. This is true, but irrelevant. Section 4 is a statute of definition and, of course, the definitions are to be applied prospectively. That would be so if the word “shall” were omitted. However, a definition to operate in the future may bring within its sweep *102persons or things because of past events or transactions, as if a law should read “Lawyers shall mean and include every person who has passed the bar examination or who may hereafter graduate from a law school.” The definition would be prospective, but those who had passed the bar examination theretofore would nevertheless come within it.
Insofar as the first decision gave a construction contrary to what we have hereinabove said, it is withdrawn. We continue, however, to cleave to that part of the earlier opinion which relates to the subjects of “substitute teachers”, “assigned substitutes” and the ratification of teacher contracts.
The judgment of the circuit court is therefore affirmed.