1- townshipsroad totenaeñtSUofe1’ gaitty" of con-Appellant relies for reversal upon two propositions: (1) That the contract entered into between the township trustees and plaintiff is prohibited by Section 1527-sl5, Supplement to the'Code, 1918; *262and (2) that the same is contrary to public policy and void.
The two propositions are so closely related that they will be considered together. Without setting out the contract in detail, it provided substantially as follows: That appellee should make contracts for dragging the roads, supervise the work on draggable roads, keep approaches to culverts and bridges and the openings to all culverts and drainage ditches in good repair, the roadside free from weeds, brush and other material, use such tools and -methods as are necessary to keep the roadway rounding in shape, do all permanent grading work, in accordance with the plans and instructions of the county engineer, work out and supervise poll taxes, report unsafe culverts and bridges, notify owners to cut and destroy all noxious weeds, employ such assistants as were necessary, at a compensation to be approved by the board of trustees, certify itemized bills for dragging, maintenance or repair work, make report of all work done by himself and assistants, and perform other designated services.
Section 1527-sl3, Supplemental Supplement, 1915, pro-' vides:
a* » gaj(| superintendent or superintendents shall have general supervision of all dragging and repair work on the township road system, including the placing of temporary culverts, and the term of office and compensation of such superintendent or superintendents shall be at the discretion of. the township trustees. The superintendent shall see that the approaches to all bridges on said roads are maintained in such manner as to present smooth and uniform surfaces, and keep the openings to all culverts and ditches free from weeds, brush and other material that will in any manner prevent the free discharge of surface water. He shall have charge of all draggable roads of the township road system and make contracts for dragging, and shall see that all draggable roads of the township road system *263are properly dragged at such times as are necessary to maintain such roads in smooth condition, at such price as is reasonable and necessary to secure such contracts, to be fixed by the township trustees. For this purpose there shall be expended under the direction of the township trustees, through the road superintendent, upon the township road system not less than the one mill drag tax now authorized by law. The township trustees shall not allow any bills for dragging, 'maintenance, or repairs work, nor shall warrants in payment therefor be drawn by the township clerk upon funds of the township road system until itemized bills therefor have been certified to by the town, ship road superintendent. A violation of this-section shall •render the toivnship clerk liable on his bond for the amount of said warrant. The compensation of such superintendent for all duties except any dragging- actually performed by him, and the cost of all equipment for dragging, shall be paid for out of the township road funds. He shall at least once a year, or on demand, furnish the township trustees a report of all work done under -and by him.”
Section 1527-sl5, Supplement to the Code, 1913, provides :
íí* * * No member of the highway commission, * * * road superintendent or any person in their employ * ' * shall be, either directly or indirectly, interested in any contract for the construction or building of any bridge or bridges, culvert or culverts or any improvement of any road or parts of road coming under the provisions of this act.”
If the contract in question comes within the purview of this statute, it is void, and plaintiff could not recover for services rendered thereunder.
Without restatement of the above enumerated matters, it will be noticed that, by specific reference, the inhibition *264of the statute ajiplies only to contracts for the construction or building of bridges or, culverts, or the improvement of roads or parts of roads coming under the provision of the statute. “Improvement Avork,” as that term is used, must be done in accordance Avith plans and specifications furnished by a county engineer, and an application must be made by the toAvnship trustees to the board of supervisors before such Avork can be done, but, upon application’s being" made, the board shall furnish an engineer, to be paid out of the county fund, Avhose duty it shall be to survey and lay off such roads according to the plans and specifications provided for the county road system, and the work shall be done in accordance therewith. Sections 1527-S9 and 1527-sl4, Supplemental Supplement, 1915.
a. Statutes : construction: prohibitory statutes: expression of one thing excludes another. Section 1527-sl3, quoted above, is permissive in character, and prescribes the duties of a person employed as highway superintendent; while Section 1527-sl5 is restrictive, and enumerates the things he must not do after becoming highway superintendent. The two sections are not in conflict, and it Avill be presumed that the legislature included in the latter section all that it deemed important or necessary to prohibit, and, by implication at least, left the township trustees free to contract in relation to all matters not included within the prohibitory provisions of the statute.
None of the sendees for which appellee claims compensation comes within the prohibited list. It is true that the services include work and the labor done by his teams and men employed by him, and also the superintending of Avork upon the ‘highway; but it does not appear that duplicate charges, for work and labor and services Avhile superintending are included in the itemized statements filed with the township trustees. The superintendent, of course, could not charge for services as a laborer and at the .same time *265for services as superintendent. None of the services rendered was under a contract directly or indirectly relating to “the construction or building of any bridge or bridges, culvert or culverts, or any ■ improvement of any road or parts of road coming under the provisions of this act,” but all services rendered were of the class permitted by the statute and enumerated in his contract with the township trustees. Unless, therefore, the contract in question is, as claimed by counsel for appellant, contrary to public policy, the finding and judgment of the lower court must be affirmed.
3' iegantyCof obpubiicetpóiiey: tatendentT’Fn-1" consistent rights ana duties. It is claimed by counsel that the contract under consideration is ruled by the decisions of this court in Bay v. Davidson, 133 Iowa 688, and James v. City of Hamburg, 174 Iowa 301, and other cases of like tenor, and that same is clearly contrary to public liolicy. The term “public policy” is of indefinite and uncertain definition, and there is no absolute rule or test by which it can always be determined whether a contract contravenes the public policy of the state, but each case must be determined according to the terms of the instrument under consideration and the circumstances peculiar thereto. In general, however, it may be said that any contract which conflicts with the morals of the times or contravenes any established interest of society is contrary to public policy. We must look to the Constitution, statutes and judicial decisions of the state to determine its public policy, and that which is not prohibited by statute, condemned by judicial decision, nor contrary to the public morals, contravenes no principle of public policy. Spead v. Tomlinson, (N. H.) 59 Atl. 376; Lipscomb v. Adams, (Mo.) 91 S. W. 1046; McGuffin v. Coyle & Guss, (Okla.) 85 Pac. 954; Lawson v. Cobban, (Mont.) 99 Pac. 128; Atlantic Coast Line R. Co. v. Beazley, *266(Fla.) 45 So. 761; Brooks v. Cooper, (N. J.) 26 Atl. 978; Veazey v. Allen, (N. Y.) 66 N. E. 103; McClanahan v. Breeding, (Ind.) 88 N. E. 695.
In the oases cited by counsel for appellant, the doctrine contended for was applied to transactions in which a public officer was involvéd, and they were cases in which, even though no actual fraud was charged, the officer might, in the performance of his public duty, be placed in a situation where he would be required to choose between his private interests and that of his constituency. It is the public policy of the government, state and national, to require all public officials, in the performance of the duties of their office, to subordinate every private interest to the public welfare, and to avoid transactions of every kind which may place private interests in antagonism to public duty. It is true that while, in the performance of his duties, a superintendent renders other services than as a laborer, they are confined to matters not prohibited by the statute; and in no way conflict with the interests of society or public welfare. He must keep a record of the time and services rendered upon the highway by men employed by him or working under his supervision, prepare an itemized statement thereof, certify that same is true and correct, and file the same with the township trustees, who alone are charged with the duty of passing upon the correctness thereof and allowing or rejecting the same. If the charges made by the superintendent are in accordance with the schedule set out in his contract, and he has correctly kept the time of the men and teams working, his claims should be allowed; otherwise, altered or modified to conform to the facts. ' Of course, some reliance must be placed by the township trustees upon the integrity of the highway superintendent, but it may be presumed that the trustees will, in the exercise of their discretion as public officers, look well to the character of men selected for this position, and that they will also exercise *267the discretion which the statute gives them of promptly terminating the contract with a superintendent found unworthy. There is no greater risk involved in the transaction in question than is present in every transaction founded upon contracts of employment. The authority conferred upon the township trustees safeguards the taxpayers and secures them against any danger of imposition or fraud on the part of the highway superintendent.
We reach the conclusion that the contract under consideration is not one prohibited by law, and that it is not contrary to public policy. The judgment of the lower court is, therefore, — Affirmed.
Gaynor, C. J., Weaver and Preston, JJ., concur.