Judgment Chandurkar, C.J.: 1. These petitions as well as several other petitions which have all been filed by teachers who hold teachers certificates issued by the Karnataka Secondary Education Examination Board, raise a question which is of considerable importance to a large body of teachers, who claim that they are entitled to be appointed as teachers in the schools in the State of Tamil Nadu. 2. The Tamil Nadu Recognised Private Schools (Regulation) Act, 1973 (hereinafter referred to as the 1973 Act), came into force on 1-12-1974. the Act was enacted for the purpose of regulation of recognised private schools in the State of Tamil Nadu. Prior to this enactment, the affairs of the educational institutions in Tamil Nadu were controlled by the Government of Tamil Nadu in accordance with what were called Educational Rules made from time to time. The Educational Rules prescribed qualifications for different kinds of teachers. 3. After the 1973 Act came into force, the appointment of teachers and their qualifications were mainly governed by the provisions of section 19 of the Act and the Rules made thereunder. Section 19 of the Act enabled the Government to make rules regulating the number, qualifications and conditions of service (including promotion, pay, allowances, leave, pension, provident fund, insurance, age of retirement and disciplinary matters etc.,) of the teachers and other persons employed in any private school. The rule-making power of the Government is contained in section 50. In exercise of this ruler making power, the Government of Tamil Nadu made the Tamil Nadu Recognised Private School (Regulation) Rules, 1974 (hereinafter referred to as the rules). These rules were amended from time to time. Rule 15 of the Rules dealt with qualifications and conditions of service of teachers and other persons. By the amendment made in 1975, Rule 15(6) provided that, “teachers and other persons employed in a private school shall possess the qualifications specified in Annexure V.” 4. We are concerned with item 3 of Annexure V., which deals with qualifications for appointment as a secondary grade teacher. Item 3 reads as follows: Secondary Grade Teacher. (1) S.S.L.C. (2) T.S.L.C. of Secondary Grade or its equivalent Provided teachers who have passed the Nursery, Montessori and Kindergarden School Leaving Certificate examination of Secondary Grade shall be employed to handle standards I and II only.” 5. Item 3 reads as follows: Secondary Grade Teacher. (1) S.S.L.C. (2) T.S.L.C. of Secondary Grade or its equivalent Provided teachers who have passed the Nursery, Montessori and Kindergarden School Leaving Certificate examination of Secondary Grade shall be employed to handle standards I and II only.” 5. In view of section 19 read with Rule 15 and Annexure V, the qualification for being appointed as a secondary grade teacher was that he should possess a Secondary School Leaving Certificate and, in addition he must also possess a Training School Leaving Certificate for Secondary Grade or its equivalent. Now, so far as the State of Tamil Nadu was concerned, the Training School Leaving Certificate was given after undergoing a course of two years at the Teachers Training Institutes, whether run by the State Government or by private recognised institute. The Training School Leaving Certificate is now known as Diploma in Teachers Education. 6. It is not disputed that before 1973 Act came into force, almost for over a period of 20 years, teachers who had obtained a certificate from the Karnataka Secondary Education Examination Board - we shall refer to this certificate as the Karnataka certificate - were given appointments in Schools in Tamil Nadu, and for all intents and purposes the Karnataka certificate was equated with the T.S.L.C. issued by Government of Tamil Nadu. This state of affairs continued till 5-8-1981. Till that date, the teachers who were appointed in private schools had to get their certificates approved by the Director of School Education. These certificates were approved almost as a matter of course, because they were treated as equivalent of T.S.L.C. of Secondary Grade, thereby satisfying the requirement of Annexure V. Consequent upon recognition of these teachers by a process of what the department called ‘evaluation’, schools were also entitled to get Government grants for paying their salary. 7. On 5-8-1981, the Government in the Education Department issued an order in G.O.Ms.No.1667, dated 5-8-1981. This order refers to a communication from the Director of School Education dated 27th March, 1981, in which the Director indicated that the Karnataka certificate is not equivalent to the certificate issued by the State of Tamil Nadu. 7. On 5-8-1981, the Government in the Education Department issued an order in G.O.Ms.No.1667, dated 5-8-1981. This order refers to a communication from the Director of School Education dated 27th March, 1981, in which the Director indicated that the Karnataka certificate is not equivalent to the certificate issued by the State of Tamil Nadu. The Director, therefore, sought orders of the Government for issuing suitable instructions “to stop the appointment of teachers trained in Karnataka State in schools situated in Tamil Nadu until the number of unemployed Secondary Grade Teachers trained in Tamil Nadu is wiped out.” The Director also requested the Government “to permit him to stop the evaluation of these certificates with immediate effect.” The G.O. recites that the Government “accept the suggestions of the Director of School Education, Madras and permit him to defer the evaluation of the Teachers Training Certificate of Karnataka State with immediate effect.” A further direction which was permitted to be given by the Director was in the following terms: “The Director of School Education is also permitted to issue necessary instructions to defer appointment of Karnataka State Teachers Certificate holders as Secondary Grade Teachers in Middle or Higher Elementary Schools till the candidates possessing Secondary Grade or Senior Basic Grade Training School Teachers Certificates issued by the Director of Government Examinations. Madras are appointed.” Consequent upon this G.O. a large number of teachers who had already obtained the Karnataka certificates and had also been given appointments in private schools, found that their certificates were not being evaluated and they therefore filed a large number of petitions in this Court for Mandamus, requiring the authorities to approve with evaluation the appointment of the petitioners as Secondary Grade Teachers from the date of their appointment. The petitioner in W.P.No.7286 of 1982, had obtained the Karnataka Certificate on 8-7-1981 and had joined as a temporary secondary grade teacher in R.C.Middle School, Siluvaipatti, Tuticorin taluk, in Tirunelveli District. Since the order of 1981 came in the way of his Karnataka certificate being evaluated, he prayed for the Mandamus, as indicated above. 8. The petitioner in W.P.No.7286 of 1982, had obtained the Karnataka Certificate on 8-7-1981 and had joined as a temporary secondary grade teacher in R.C.Middle School, Siluvaipatti, Tuticorin taluk, in Tirunelveli District. Since the order of 1981 came in the way of his Karnataka certificate being evaluated, he prayed for the Mandamus, as indicated above. 8. The petitioners who came to this Court complaining against the refusal of the Director of Education to evaluate Karnataka certificates and treat them as being equivalent to the T.S.L.C. as contemplated by Annexure V of the rules, fell in three categories as follows: (i) Teachers who obtained Karnataka Certificates before 5-8-1981 which were evaluated before 5-8-1981; (ii) Teachers who obtained their Karnataka Certificates before 5-8-1981, but the certificates were not evaluated; and (iii) Teachers who obtained their certificates after 5-8-1981 and whose certificates were not evaluated. 9. The occasion for the first category of teachers to approach this Court arose, because consequent upon the issue of G.O.Ms.No.1667 dated 5-8-1981, the authorities seemed to be withholding the grants to which the private schools were otherwise entitled to. Some of these petitions came up before Rama-nujam, J. who on 10-11-1982 passed a common order in W.P.Nos.10817 of 1981 and 6520 and 6521 of 1982. The learned Judge took the view that on the relevant date, i.e. 5-8-1981, there was a valid evaluation made by the Director of School Education under Rule 14 of the Education Rules of the certificates issued by the Karnataka Board as equivalent to the similar certificates issued by the State of Tamil Nadu and so long as that evaluation continued to subsist, the petitioners were entitled to be considered for appointment in the State of Tamil Nadu, and their applications could not be rejected merely on the ground that they were holders of the Karnataka State Teachers Training Certificates. The learned Judge found that the evaluation of the petitioners’ certificates had been made long before the issue of G.O.Ms.No.1667, and that G.O. did not specifically say that the evaluations already made will stand wiped out. The learned Judge therefore took the view, that the State authorities could not ignore the earlier evaluations without cancelling or setting aside the same after giving notice to the persons concerned. The learned Judge therefore took the view, that the State authorities could not ignore the earlier evaluations without cancelling or setting aside the same after giving notice to the persons concerned. Consequently the order dated 14-8-1981 under which instructions were given by the Director consequent upon the issue of the G.O. dated 5-8-1981 to the effect that Inspecting Officers should not approve appointment of Karnataka State Teachers Certificate-holders as Secondary Grade Teachers its Middle or Higher Elementary Schools till the candidates possessing Secondary Grade or Senior Basic Grade Training School Teachers Certificates issued by the Director of Government Examinations, Madras are appointed was quashed. 10. In these petitions we are now concerned with the other two categories of teachers. Out of a large number of teachers who have secured their certificates a very small number of teachers have secured the certificates after 5-8-1981; but in none of these cases have the certificates been evaluated obviously in view of G.O.Ms.No.1667 dated 5-8-1981. These writ petitions have been pending for quite some time. During the pendency of these writ petitions, the Government came up with another G.O.Ms.No.1236 dated 17-9-1984. By this G.O. the Government notified that they had examined the matter carefully with regard to the equivalence of the Karnataka certificate with the T.S.L.C. and laid down certain criteria which the Director of School Education was to observe while evaluating the Karnataka State Teachers Training certificates. These criteria were as follows: “(i) Teachers Training Certificates holders of Karnataka State should have passed their S.S.L.C. in Tamil Medium with Tamil as I language or should have taken Tamil as I language in S.S.L.C. if they have studied in English Medium. (ii) They should have obtained 50% of marks in aggregate in their S.S.L.C. as in the case of Teachers Training Certificate-holders of Tamil Nadu; (iii) They should have obtained 50% of marks in each subject in their Teacher Training Certificate as in the case of Teacher Training Certificate-holders of Tamil Nadu. (iv) If they studied in other than Tamil Medium in their S.S.L.C. as well as Teachers Training Certificates and satisfied the conditions 283 their Certificate may be evaluated with a condition that they are eligible for appointment as Secondary Grade Teachers in Tamil Nadu only in Schools where medium of instructions is other than Tamil. (iv) If they studied in other than Tamil Medium in their S.S.L.C. as well as Teachers Training Certificates and satisfied the conditions 283 their Certificate may be evaluated with a condition that they are eligible for appointment as Secondary Grade Teachers in Tamil Nadu only in Schools where medium of instructions is other than Tamil. The Government also permit the Director of School Education to apply the above conditions while evaluating the Teachers Training Certificates of all other States in order to ensure uniformity and consistency.” 11. When this G.O. came to be issued, the stand taken by the State Government was, that all requests for evaluation of the Karnataka Certificates which were pending on 17-9-1984 would be considered in accordance with the conditions laid down in G.O.Ms.No.1236. The teachers were obviously aggrieved by this stand and they were therefore given an opportunity to amend the writ petitions, if necessary, and state the grounds on which they were entitled to challenge the G.O. dated 17-9-1984. Additional affidavits have been filed in some cases which raise a challenge basically to what is described as retrospective effect of the G.O. dated 17-9-1984. We shall consider this a little later. 12. It is however, obvious that merely by issuing G.O.Ms.No.1236, dated 17-9-1984, the petitioners’ main grievance that they were entitled to have their Karnataka Certificates declared as being equivalent to the T.S.L.C. does not cease to survive; and we have, therefore, heard the petitioners on the validity of both G.O.Ms.No.1667 dated 5-8-1981 and G.O.Ms.No.1236 dated 17-9-1984. Learned Counsel appearing for the petitioners, namely, Mr,Martin, Miss.Anna Mathew, Mr.Balasubramanian and Mr.Balasundaram were heard. In addition, we also heard Mr.Padmanabha Rao who appeared in W.P.No.8156 of 1983 in which also the validity of G.O.Ms.No.1236 dated 17-9-1984 is challenged. 13. Mr.N.R.Chandran, the Additional Government Pleader has appeared for the Government in support of the stand that the Government was entitled to prescribe standards or criteria on which a Karnataka Certificate could be decided as being equivalent to T.S.L.C. He was supported by Mr. Balasundaram, who is appearing for the Association of Unemployed Teachers in Tamil Nadu which had filed W.P.No.8800 of 1984, making a grievance that the education authorities were not implementing G.O.Ms.No. 1667, dated 5-8-1981 and a Mandamus should therefore, be issued to the Government to give effect to G.O.Ms.No. 1667 dated 5-8-1981. Balasundaram, who is appearing for the Association of Unemployed Teachers in Tamil Nadu which had filed W.P.No.8800 of 1984, making a grievance that the education authorities were not implementing G.O.Ms.No. 1667, dated 5-8-1981 and a Mandamus should therefore, be issued to the Government to give effect to G.O.Ms.No. 1667 dated 5-8-1981. As a matter of fact, the mandate asked for is in positive terms that the Director of School Education, the Chief Education Officer and the State of Tamil Nadu should not equate the Karnataka certificate with that of Tamil Nadu certificate for appointment to Secondary Schools in Tamil Nadu. 14. Learned counsel appearing on behalf of the petitioners have contended that the real intent and purpose of issuing G.O.Ms.No.1667, dated 5-8-1981 was to give preference to unemployed teachers who held the Tamil Nadu certificate but were not being appointed and that all appointments were being made from among the teachers who had obtained the Karnataka certificates. Reliance was placed on the counter-affidavit filed on behalf of the State Government in which according to the learned counsel the fact that Karnataka Certificate was equivalent to the Tamil Nadu Certificate was accepted. According to the learned Counsel, what was intended to be achieved by the G.O.Ms.No.1667, dated 5-8-1981 was to wipe out unemployment of teachers from Tamil Nadu and it could not be a valid criterion for not evaluating the Karnataka Certificate of the teachers. The learned counsel also contended that the G.O. dated 17-9-1984 was really intended to carry out the purpose and object with which the 1981 G.O. was issued, and if the G.O. dated 5-8-1981 was quashed, the G.O. dated 17-9-1984 was also liable to be quashed. A large part of the argument urged before us was on the footing that it was not open to the Government by an executive order like the G.O. dated 17-9-1984, to give it a retrospective effect so as to adversely affect the rights of teachers who had obtained Karnataka Certificates and who were entitled to have their certificates evaluated, because it had always been treated as being equivalent to the Tamil Nadu certificate in the past. The learned counsel appearing on behalf of the petitioners, however, very fairly conceded that if the Tamil Nadu Government wanted to lay down guidelines for the purposes of ascertaining the equivalance of Karnataka certificate with the Tamil Nadu certificate, it is undoubtedly open to the Tamil Nadu Government to do so, but contended that this could be done only prospectively, with the result that only certificates obtained after 17-9-1984 could be dealt with on the footing of the criteria laid down in the G.O. dated 17-9-1964. We shall now consider these contentions. 15. At the very outset, it is necessary to properly appreciate the G.O. dated 5-8-1981 in the light of the counter affidavit which has been filed by the State. Undoubtedly, W.P.Nos.10718 and 10909 of 1981 are on board for hearing. Before going to the counter affidavit, it is necessary to scrutinise carefully the G.O. dated 5-8-1981. In the first paragraph of the G.O. reference is made to the fact that the Director of School Education has indicated that the Karnataka State Teachers Training Certificate is not equivalent to the certificate issued by the State of Tamil Nadu. In the same paragraph, reference is made to the suggestion made by the Director of School Education that suitable instructions might be issued to stop the appointment of teachers trained in Karnataka State in schools situated in Tamil Nadu, until the number of unemployed Secondary Grade Teachers trained in Tamil Nadu is wiped out. In the same paragraph the request of the Director is noted by which he asked for permission to stop the evaluation of the certificates with immediate effect. Carefully read, it cannot be seriously doubted that the Director of School Education had indicated to the Government that the Karnataka Certificate is not equivalent to the Tamil Nadu Certificate. In the same paragraph the request of the Director is noted by which he asked for permission to stop the evaluation of the certificates with immediate effect. Carefully read, it cannot be seriously doubted that the Director of School Education had indicated to the Government that the Karnataka Certificate is not equivalent to the Tamil Nadu Certificate. But when the G.O. made reference to the instructions which were sought by the Director, it appears that the instructions were sought not with a view to stop the evaluation of the Karnataka certificate permanently, but the evaluation was requested to be stopped for a certain period of time; and as the G.O. itself put, this period of time was "until the number of en-employed Secondary Grade Teachers trained in Tamil Nadu is wiped out.” This indicates that even according to the Director, if the teachers in Tamil Nadu could be absorbed, then even he did not see any difficulty in appointing teachers holding Karnataka certificates. When we go to the second paragraph of the G.O. it is important to bear in mind that what the Government permitted the Director to do was "to defer the evaluation of the Teachers Training Certificate of Karnataka State with immediate effect.” This clearly indicates that there was no ban on the evaluation of the Karnataka certificates, but the evaluation was being merely postponed. As if to make the matter clear, in the last sentence in the G.O. what the Director was asked to do is to issue necessary instructions “to defer appointment of Karnataka State Teachers Certificates-holders as Secondary Grade Teachers … till the candidates possessing Secondary Grade or Senior Basic Grade Training School Teachers Certificates issued by the Director of Government Examinations, Madras are appointed. The direction to defer the evaluation was, therefore, to be operative only as long as teachers holding the Tamil Nadu certificate were not appointed. We do not see how the operative part of the G.O. dated 5-8-1981 can be construed as even remetely suggesting that the Government had accepted the suggestion of the Director that the Karnataka certificate should not be treated as being equivalent to the Tamil Nadu certificate. We do not see how the operative part of the G.O. dated 5-8-1981 can be construed as even remetely suggesting that the Government had accepted the suggestion of the Director that the Karnataka certificate should not be treated as being equivalent to the Tamil Nadu certificate. As a matter of fact, indication is to the contrary, because if the Karnataka Certificate-holders could be appointed after the un-employed teachers holding Tamil Nadu Certificates were all provided for this could not have been done unless the Karnataka Certificate was treated as being equivalent to the Tamil Nadu certificate for the purposes of Annexure V. We are, therefore, unable to read the G.O. dated 5-8-1981 as containing the decision of the State Government that the Karnataka Certificate ceased to be equivalent to the Tamil Nadu Certificate. 16. If there is any doubt about the object and effect of this G.O. dated 5-8-1981, the matter stands clarified by the averments made in the counter affidavit filed the Writ Petitions where an express challenge was made to G.O. dated 5-8-1981. As if to pin-point the controversy involved, in most unmistakable and unambiguous terms, the counter affidavit in paragraph 2 stated as follows: “The salient point governing the whole issue is that while thousands of candidates who were regularly trained in Tamil Nadu are unemployed, persons who took the training in Karnataka are appointed as teachers. If this is allowed to continue, all the Tamil Nadu trained teachers will never get teachers jobs and they will be put to hardship.” These averments give an indication as to what was at the back of the mind of the authorities, when they issued G.O. dated 5-8-1981. They did not question any equivalance between the two certificates as a major issue, but the salient point even according to them was that, if Karnataka certificate-holders were given appointments in Tamil Nadu, then teachers who hold Tamil Nadu certificates, of which category there were a large number would never be appointed. The whole object of this G.O. dated 5-8-1981 was clearly to put a ban on Karnataka State Certificates-holders from being appointed in posts for which the Government wanted the unemployed teachers in Tamil Nadu to be appointed, an approach which is wholly contrary to the guarantee of equality of opportunity in the matter of employment found in Article 16 of the Constitution of India. In paragraph 7 of the said counter-affidavit, there is a clear admission that the Karnataka Certificate has been treated as equivalent to the Teachers Training Certificate of Secondary Grade issued by the authorities of Tamil Nadu. A contention is raised by the petitioners that both these certificates have been treated as equivalent of each other. While dealing with this contention, the averment in paragraph 7 is, “it is submitted that though these certificates are equivalent to that of secondary grade of Tamil Nadu, evaluation has been stopped only for reason stated in para 4 and evaluation is not a formal act as alleged. In the same paragraph it is further averred as follows: “When teachers were not available in Tamil Nadu teachers from other States came and they were evaluated. Now with a glut in Tamil Nadu with thousands of unemployed teachers, it is the duty of the Government to regulate when particularly it was even brought to their notice that Karnataka Certificates are actually inferior academically as explained above and States like Kerala are taking very serious action on the same issue in this State.” 17. Reference is undoubtedly made in paragraph 4 to the effect that there is a difference between the certificates issued in Tamil Nadu and those issued in Karnataka. This itself lies, according to the affidavit in the fact that the educational qualification for admission to the Secondary Grade Training, though in both States is S.S.L.C. in so far as Tamil Nadu is concerned, the minimum marks for admission in Teachers Training Institutes is 300 in S.S.L.C. the minimum passing marks are 50% and the syllabus in Tamil Nadu lays emphasis on Tamil language as the medium of instruction while in Karnataka there is no minimum prescribed for admission, the minimum passing marks are 35% and there is no emphasis on Tamil language. While we cannot dispute the right of the educational authorities and, indeed of the State Government, to lay down the criteria on considerations which must essentially be academic on which the question of equivalence of the two certificates can be properly determined, we are primarily concerned with the question, whether the G.O. dated 5-8-1981 can be read as containing a decision of the State Government not to recognise the Karnataka certificates after 5-8-1981. That there is a difference in academic standards or with regard to the passing marks or with regard to minimum marks for seeking admission to the certificate course, may be a good ground for reviewing the equivalence which held the field for almost 20 years; but what we are concerned with is, whether the Government has reached the decision not to equate the two certificates on 5-8-1981. Even in paragraph 4, emphasis is laid on the plight of the unemployed teachers who could not get employment in Tamil Nadu with the result that the Government was forced to restrict the admissions in the Teachers Training Institutes not only numerically but even period-wise; the admissions were made only in alternate years. It is obvious from the averments made in the counter affidavit that the Government was impelled to take the decision of stopping evaluation of the Karnataka certificates only because there is a large number of unemployed teachers with T.S.L.Cs. and not because it is not equivalent. In W.P.No.8156/83, the letter of the Director of School Education dated 30-12-81 is produced in which he states that Karnataka certificate is equivalent to T.S.L.C. but in view of G.O.No.1667 under orders of Government evaluation is stopped. We may also refer to the averments in paragraph 10 of the counter affidavit in which the Government really came out with the object with which G.O.Ms.No.1667, was issued. Paragraph 10 of the counter-affidavit reads as follows: It is most respectfully submitted that orders in G.O.Ms.No.1667, Education, dated 5-8-81 were issued for the welfare of about 15,000 unemployed Secondary Grade trainees in Tamil Nadu; Government issued orders only to stop evaluation for the teacher's certificate of the Higher Examination of Karnataka and Instructions were issued not to approve such appointments and also to give preference to the holders of the Secondary Grade training in Tamil Nadu, as the policy of the Government is to solve the unemployment problem.” These averments in paragraph 10 justify the construction which we have placed on the real intent and purpose and effect of G.O.Ms.No.1667. The effect of G.O.Ms.No.1667 was, therefore, not dereognition of the equivalence of the Karnataka Certificate with the Tamil Nadu Certificate, but merely to postpone the evaluation until the unemployed teachers who held the Tamil Nadu certificate had secured employment. As already pointed out, such an approach would be wholly impermissible. The effect of G.O.Ms.No.1667 was, therefore, not dereognition of the equivalence of the Karnataka Certificate with the Tamil Nadu Certificate, but merely to postpone the evaluation until the unemployed teachers who held the Tamil Nadu certificate had secured employment. As already pointed out, such an approach would be wholly impermissible. Once the two certificates are treated as equivalent of each other, the State could not show any preference to any particular class of teachers merely on the ground that they were holders of certificates issued by an institution in Tamil Nadu. 18. Once we place this construction on the G.O. dated 5-8-1981, the natural result would be that equivalence of the Karnataka certificate with the Tamil Nadu certificate would continue to be effective till 17-9-1984 when the G.O.Ms.No.1236 was issued. The only impediment for the evaluation of the certificates of the Karnataka certificate holders was G.O. dated 5-8-1981. Once that is out of the way in view of the construction placed upon it, then obviously whatever certificates were submitted to the State Government till 17-9-1984 would have to be dealt with on the footing that the Karnataka certificate was equivalent with the Tamil Nadu certificate. 19. The learned Additional Government Pleader has referred us to certain decisions in support of the proposition that it is open to the State Government to deal with the question of equivalence of two educational qualifications on the basis of a valid reason. The three decisions on which reliance was placed were, MISS. SATHYA RAO v. UNIVERSITY OF MADRAS MISS. SATHYA RAO v. UNIVERSITY OF MADRAS (1977)2 MLJ.403; MEENAKSHI SUNDARAM v. DIRECTOR OF LEGAL STUDIES MEENAKSHI SUNDARAM v. DIRECTOR OF LEGAL STUDIES (1981)2 MLJ.141 and PUNJAB UNIVERSITY v. DEVJANI CHAKRABARTI PUNJAB UNIVERSITY v. DEVJANI CHAKRABARTI (1984)3 S.C.C. 612 =A.I.R.1984 S.C.1444. In the University of Madras case cited supra, the question which fell for consideration before the Division Bench of this Court was, whether it was within the powers of the Syndicate of the Madras University to lay down conditions for admission; and in that context after referring to the decision in KRUSE v. JOHNSON KRUSE v. JOHNSON (1898)2 Q.B.91 and to another decision in ASSOCIATED PROVINCIAL PICTURE HOUSE LTD. v. WEDNESBURY CORPORATION ASSOCIATED PROVINCIAL PICTURE HOUSE LTD. v. WEDNESBURY CORPORATION ASSOCIATED PROVINCIAL PICTURE HOUSE LTD. v. WEDNESBURY CORPORATION (1948)1 K.B.223, the Division Bench observed as follows: “The above pronouncements make it clear that a Court cannot sit in judgment as if it were an Appellate Authority over the wisdom of a particular body which made the subordinate legislation or passed the by-law or prescribed the conditions or qualifications and come to a conclusion differing from the one which that body took on the reasonableness or otherwise of such subordinate legislation, by-laws or conditions or qualifications. The principle is that only when it is established that no reasonable person could have come to such a conclusion or could have made such a by-law or subordinate legislation, the Court can interfere. It should not be forgotten that in the present case the body which was entrusted with the power of the Syndicate of the University which may be considered to be. an expert body in relation to matters of education. Whether one considered it to be an expert body or not, the legislature thought fit to consider such a body as an expert body on matters relating to education and has chosen to confer the power on such a body. Therefore unless the Court is convinced that the conditions prescribed in the present case are so unreasonable as no reasonable person would have come to or are alien or foreign to the purpose for which the power was conferred on the Syndicate, the Court cannot hold that the conditions imposed by the Syndicate are unreasonable as to avoid the same.” 20. There can be hardly any quarrel with the view taken by the Division Bench. It is not the case of the petitioners, nor would it be possible to go into the question if it is raised that this Court must go into the question as to whether the equivalence has been made properly or not, that is, whether a certificate or degree granted by one educational institution stands a fair comparison in academic quality and excellence with the certificate or degree granted by another educational institution, be it a University or Board, as that is a matter which is within the special competence of the educational authorities. The educational authorities are alone the proper authorities who can compare the nature of the educational course and the nature of the instruction on the basis of which the certificates or degrees are granted; and unless it is shown that a decision of the educational authorities is so perverse or so unreasonable or arbitrary that no reasonable person would arrive at such a decision, this Court would not interfere with such decision on academic matters under Article 226 of the Constitution of India. As already observed, so far as the further criterion given in the G.O. dated 17-9-1984 are concerned, there is no challenge by any of the petitioners. The only challenge made was that, all pending applications for evaluation should not be decided in accordance with the criteria laid down on 17-9-1984. We have already pointed out that when the decision of the State Government to treat the equivalence which so far was operative as being in-operative, is taken for the first time on 17-9-1984, then the Karnataka certificate holders had a right to have their certificates evaluated on the basis of such equivalence. It would be only in cases where evaluation is necessary after 17-9-1984, that the criteria laid down in G.O.Ms. No.1236 would have to be considered. 21. The other decision in MEENAKSHI SUNDARAM v. DIRECTOR OF LEGAL STUDIES MEENAKSHI SUNDARAM v. DIRECTOR OF LEGAL STUDIES (1981)2 MLJ.141 turned on whether a degree obtained on the basis of a correspondence course could be taken into account for the purposes of admission to the B.L. course. The petitioner in that case held a B.G.L. Degree of Madurai Kamaraj University, obtained after pursuing the correspondence course. The rules prescribed by the Bar Council permitted only a student who had obtained a B.C.L. Degree after attending regular classes to take the B.L.course. This was challenged on the ground of violation of Article 14 and the challenge was negatived. It was held that the rules were well within the rule-making power of the Bar Council. While dismissing the petition, the Division Bench observed that the degree obtained after pursuing the correspondence course cannot be equated, in all circumstances, and in ail respects with a degree obtained after attending regular classes, and, if a particular body or organisation or association treats the two degrees as equal for certain purposes, that cannot make the two degrees equal in reality or for all purposes. We do not see the relevancy of this decision, so far as the facts of the present case are concerned. 22. The one and the only purpose for which equivalence was claimed was the purpose of obtaining employment as teacher. It is not the case either of the petitioners or of the State Government that the Karnataka certificate is equivalent to the Tamil Nadu certificate for some purposes and not for other purposes. Either the one is equivalent of the other or it is not for the purpose of appointment as a teacher in Tamil Nadu. 23. In the third decision of the Supreme Court, viz., PUNJAB UNIVERSITY v. DEVJANI CHAKRABARTI viz., PUNJAB UNIVERSITY v. DEVJANI CHAKRABARTI (1984)3 S.C.C. 612 =A.I.R.1984 S.C.1444 the Court was concerned with the decision of the Punjab University which had earlier equated the 12th standard examination with Part I Examination of the Degree course, while subsequently the same examination was equated with Pre-University Examination; and the Court held that subsequent decisions were prospective and valid. This decision which essentially turned on point of time with reference to whether the decision of the Syndicate was operative, is not of any assistance to the learned Government Pleader. 24. It was contended by Mr.Chandran that, if certificates which were submitted on or after 5-8-1981 are evaluated on the basis of the criteria laid down in G.O.Ms.No.1236, dated 17-9-1984, no grievance can be made that the G.O. dated 17-9-1984 is having a retrospective effect. According to the learned counsel, no vested right is being taken away merely because the certificates are of a prior date; and the application of the rules is prospective in character, because the determination of equivalence is only being done after 17-9-1984. So far as the concept of retrospective effect of either legislation or an executive order is concerned, the position is well settled. A statute is said to be retrospective only when it takes away a vested right retrospectively. But it is also well established that a statute is not retrospective merely because it affects the existing rights; nor is it retrospective merely because a part of the requisites for its action is drawn from a time antecedent to its passing. A statute is said to be retrospective only when it takes away a vested right retrospectively. But it is also well established that a statute is not retrospective merely because it affects the existing rights; nor is it retrospective merely because a part of the requisites for its action is drawn from a time antecedent to its passing. Mr.Chandran, obviously has the latter concept in mind when he contends that a certificate may have been secured prior to 17-9-1984, but merely on that ground, the G.O. cannot be said to be giving effect retrospectively. We have already pointed out that as the decision to go back on the equivalence is contained in G.O. dated 17-9-1984, the decision must be taken to have been reached only on that date. Till that date, equivalence of the two certificates having not been disturbed, there was clearly a vested right in the certificate-holders of Karnataka, which certificates were already lying with the educational authorities for their evaluation on the basis of equivalence. Any applicability of the criteria laid down in the G.O. dated 17-9-1984 to them would clearly adversely affect the rights of the Karnataka certificate-holders. 25. As part of the attack on the validity of G.O.Ms.No.1667, dated 5-8-1981 and G.O.Ms.No.1236 dated 17-9-1984, Mr.Padmanabha Rao has contended that these G.Os. purport to amend the statutory Rules of 1974 which the State Government is not compentent to do. The argument was that wherever it was intended to indicate that there was an institutional preference, a specific mention is made in service rules; and our attention was invited to Tamil Nadu State and Subordinate Services Rules, in which while specifying qualifications, it was specifically laid down in respect of certain instructions that degrees of certain Universities would be necessary. For example, in Rule 19 of Part II - General Rules which prescribes special qualifications, there is an Explanation which provides that in cases where the Special Rules prescribe a degree or diploma as a qualification then a decree or diploma granted by any of the Universities or Institutions recognised by the University Grants Commission for the purpose of its grant mentioned in Schedule II to this part shall be recognised as the qualification. Our attention was also invited to the advertisement of the Public Service Commission in W.P.No.8156 of 1983 in which while advertising the posts of Language Pandits, the qualification prescribed was "a degree of any University in the State in the language concerned (namely, Tamil, Telugu, Malayalam or Urdu) as the main subject. The argument appears to be that, when the educational authorities of the State of Tamil Nadu declined to consider a Karnataka certificate, they are, in fact, introducing in Annexure V something which is not permitted, because one of the qualifications is that the teacher must have a T.S.L.C. of Secondary Grade or its equivalent. Now, apart from the merits or effect of the two impugned G.Os., it is not possible for us to accept the contention that if the educational authorities of the State Government justifiably declined to treat any particular certificate as not being equivalent to the T.S.L.C. of Secondary Grade, they purport to amend the Rules of 1974 or the Annexure V. All that the Rules prescribe is that, a teacher for appointment as a secondary grade teacher must held two qualifications. He must hold a Secondary School Leaving Certificate and he must hold the T.S.L.C. of Secondary Grade or any other equivalent certificate. This is implict in the power to equate a certificate which is not T.S.L.C, of Secondary Grade with the certificate which is issued by Commissioner for Government examinations in Tamil Nadu. Such power by its very nature is executive in character, because once an equivalent has to be determined that function has to be performed by the executive authorities, though such a decision of treating a certificate or treating a certificate issued by an authority other than in Tamil Nadu may be open to challenge on permissible grounds. Since it was clearly permissible for the State Government and the educational authorities to decide the question of equivalence, it is not necessary to discuss the decision of the Supreme Court in STATE OF HARYANA v. SHAMSHERJANG STATE OF HARYANA v. SHAMSHERJANG (1973)1 S.C.R.249=A.I.R.1972 S.C.1546 in which the Supreme Court held that by an executive order a rule made by the Governor under Article 309 of the Constitution of India cannot be amended. 26. 26. Some decisions were cited, before us by Mr.Padmanabha Rao in support of the argument that the issuance of the two impugned averment orders suffer from the vice of arbitrariness and any attempt to give effect to the impugned G.O.Ms.No.1667, dated 5-8-1981 would result in violation of Articles 14 and 16 of the Constitution and any attempt to give retrospective effect to the second G.O.Ms.No.1236 dated 17-9-1984 TAMIL NADU A. Minimum marks for admission in Teachers Training Institutes is 300 in S.S.L.C. would also not be permissible. It is now well established that any arbitrary exercise of power per se would result in denial of equality of protection of the laws. (See A.L.KALRA v. THE PROJECT AND EQUIPMENT CORPORATION OF INDIA LTD. A.L.KALRA v. THE PROJECT AND EQUIPMENT CORPORATION OF INDIA LTD. (1984) Lab.I.C.961=(1984)3 S.C.C.316=A.I.R.1984 S.C.1361. 27. This proposition is also laid down in three other decisions which have been cited, namely, E.P.ROYAPPA v. STATE OF TAMIL NADU AND ANOTHER E.P.ROYAPPA v. STATE OF TAMIL NADU AND ANOTHER (1974) Lab. I.C.427=(1974)4 S.C.C.3=A.I.R.1974 S.C.555; M/s. KASTURLAL LAKSHMI REDDY etc. v. THE STATE OF JAMMU AND KASHMIR AND ANOTHER M/s. KASTURLAL LAKSHMI REDDY etc. v. THE STATE OF JAMMU AND KASHMIR AND ANOTHER (1980)4 S.C.C.1=A.I.R.1980 S.C.1992 and RAMANA DAYARAM SHETTY v. THE INTERNATIONAL AIR PORT AUTHORITY OF INDIA AND OTHERS RAMANA DAYARAM SHETTY v. THE INTERNATIONAL AIR PORT AUTHORITY OF INDIA AND OTHERS (1979)3 S.C.C.489=(1979)2 Lab.L.J.217=A.I.R.1979 S.C.1628. However, in view of the fact that we have already indicated that the G.O. dated 5-8-1981 cannot affect the rights of the teachers who have already obtained certificates and applied for their evaluation and that G.O.Ms.No.1236 dated 17-9-1984 cannot be given retrospective effect, it is not necessary to discuss the authorities cited by Mr.Padmanabha Rao. 28. We may, however, make it clear that so far as the impugned G.O, dated 17-9-1984 is concerned, it was clearly open to the State Government to lay down the fresh criteria for determining the question of equivalance. In the. counter affidavit to which we have referred above, the circumstances which necessitated the issue of the criteria in the impugned G.O. dated 17-9-1984 have been culled out. The averments in the counter affidavit point out the differences between the requirements of a certificate issued by the Teacher Training Institute in Tamil Nadu and similar in Karnataka. In the. counter affidavit to which we have referred above, the circumstances which necessitated the issue of the criteria in the impugned G.O. dated 17-9-1984 have been culled out. The averments in the counter affidavit point out the differences between the requirements of a certificate issued by the Teacher Training Institute in Tamil Nadu and similar in Karnataka. A comparative statement which highlights those differences, which is set out in the counter affidavit, is reproduced below? KARNATAKA No minimum marks for admission. Any one gets it for the mere asking. b. Minimum marks for pass is 50%. c. Syllabi different Tamil Nadu syllabi emphasises Tamil language as the medium of instruction in Elementary Schools. 29. The first 2 criteria for admission to the Institutes in Tamil Nadu and Institutes in Karnataka have a direct impact on the quality of teachers who obtained those certificates. If the two certificates have to be equated, then there must be a similarity in the qualitative performance which is a qualifying factor for obtaining such certificates. In Tamil Nadu, the minimum marks for admission in the Teachers Training Institutes is 50%, that is 300 in the Secondary School Leaving Certificate examination, while merely, obtaining passing marks is enough for admission in Karnataka, which has a direct impact on the educational standards of teachers who undergo the training course. Similarly, in Tamil Nadu the passing marks are 50% while the minimum passing marks in Karnataka are 35%. This again has relevance on the question as to whether the two certificates must be treated as equivalent to one another. Teachers in Tamil Nadu essentially cater to education of children whose language is Tamil, and since Tamil is the medium of instruction in elementary schools, the question as to whether syllabus of the training course lays emphasis on Tamil as the language or medium of instruction is also a relevant consideration. By its very nature, the language of Karnataka being not Tamil, it is not possible that there would be emphasis on Tamil language with the result that, when catering to the educational needs of students whose mother tongue is Tamil, putting them into the hands of teachers who may not be trained to teach in Tamil is bound to have some adverse effect. 30. 30. All these three considerations appear to be eminently proper, which have now been considered, and while laying down the criteria it is obvious that second and third criteria, by insisting upon 50% of marks in the aggregate in the S.S.L.C. and 50% of Minimum marks for pass 35%. marks in each subject in the Teachers Training Certificate examination, were intended to bring on par such teachers with the teachers who were issued certificates from the Tamil Nadu Institutes, The emphasis on Tamil has also been achieved by clauses 1 and 4 in the criteria, which while giving effect to the concept of equivalence provide that the Karnataka certificate-holders who have passed their S.S.L.C. in Tamil Medium with Tamil as the first language or have taken Tamil as first language in T.S.L.C., if they have studied in English medium, will be recognised in schools, where the medium of instruction is Tamil. Under clause 4 it is provided that if such teachers holding the Karnataka certificate have studied in a medium other than Tamil medium in their S.S.L.C. as well as Teachers Training Certificate they satisfy second and third conditions, namely, securing 50% of the marks in the aggregate and 50% of the marks in each of the subjects in Teacher Training Certificate examination, and then their recognition will be restricted only as regards eligibility for appointment as secondary grade teachers in Tamil Nadu only in schools limited to instructional needs, of other than Tamil students and as such each one of those four criteria has clear nexus with the equivalence of the certificates issued by the Tamil Nadu Institutes.- 31. In W.P.No.7286 of 1982 the certior arified mandamus sought is that the second respondent should be directed to approve with evaluation the appointment of the petitioner as a secondary grade teacher in R.C.Middle School in Siluvaipatti, Tuticorin. In W.P.No.3347 of 1982 the relief sought is that a mandamus should be issued to the second respondent, that is the Director of School Education, Madras to evaluate the petitioner's teachers certificate issued by the Karnataka Board of Secondary Education. The petitioners in the above two petitions will accordingly be entitled to that mandamus as prayed for. Both these petitions are allowed. 32. Mr.Balasubramaniam who appears in W.P.No.255 of 1984 has raised a contention which, however, does not seem to be raised even by the Government or the educational authorities. The petitioners in the above two petitions will accordingly be entitled to that mandamus as prayed for. Both these petitions are allowed. 32. Mr.Balasubramaniam who appears in W.P.No.255 of 1984 has raised a contention which, however, does not seem to be raised even by the Government or the educational authorities. He has pointed out that when condition No.3 prescribes that Karnataka certificate-holders should have obtained 50% of the marks in each subject in their teacher training certificate, there might be some difficulty in ascertaining whether these 50% marks have to be obtained separately in internal and external examinations. In the mark sheet examinations appear to be internal and external. The fourth subject really consists of two subjects, namely Science and Mathematics. Reading criteria No.3, it is obvious that the requirement is that 50% marks must be obtained in each subject. If the total number of marks of each subject even according to the mark list is made up of two elements namely, internal and external marks, then it is obvious, and indeed it is not disputed by the Additional Government Pleader, that this total of the marks obtained at the internal and external examinations will have to be taken into consideration for determining whether criteria No.3 is satisfied. Having regard to the view which we have taken, the two petitioners in W.P.NoS. 3347 of 1983 and 255 of 1984 are entitled to the mandamus soguht by them. 33. The overall effect of our decision, therefore, is that G.O.Ms.No.166, Education dated 5-8-1981 and the communication which was issued by the Director of School Education on 14-8-1981 to the Inspecting Officers not to approve the appointment of Karnataka State teacher certificate holders as Secondary Grade Teachers in Middle or Higher Schools till the candidates possessing Secondary Grade or Senior Basic Grade Training School Teachers Certificate issued by the Director of Government Examinations are appointed, ceases to be operative and is quashed. Equally the subsequent proceeding dated 11-9-1981 issued based on it, is also quashed. 34. Equally the subsequent proceeding dated 11-9-1981 issued based on it, is also quashed. 34. According to the learned counsel for the petitioners appearing in several petitions, there are cases in which the Karnataka certificates held by the respective teachers are still with the educational authorities, but they have declined to evaluate them, or in some cases such certificates were sent by the schools for evaluation to the educational authorities and they have been returned to the school authorities and still other cases wherein having regard to the communication and the attitude adopted by the educational authorities the Certificates were still lying with the school authorities, and have not been forwarded because they were not being evaluated by the department. In all these three categories of cases the certificate holders will have a right to have their certificate declared equivalent to the Tamil Nadu Certificates, provided the certificates have been handed over prior to 17-9-1984. 35. Hence all these writ petitions are allowed only regarding the aspect of evaluation of Karnataka certificate, as indicated above. No costs. Petitions allowed.