Illegal contracts are unenforceable, not because of any desire on the part of the courts to aid either party thereto, but because public interests require that they be not enforced. If the parties thereto could make them enforceable by the simple device of putting them in writing, using such words as would conceal the illegality of the objects intended by them to be accomplished, or omitting all reference to such illegality, the rules on the subject of illegality would be of but little use. Accordingly, evidence that tends to show that the written contract is illegal,1 as to show that the contract is tainted with usury,2 or is given to compound a felony;3 or that the contract is entered into for the purpose of entrapping persons into committing crimes and for securing compensation for the detection of them in such crime;4 or that the real purpose of the contract is to provide for bribing the agents of a third person;5 or that the real consideration of a promissory note is the political influence of the payee; 6 or that a contract is entered into to secure personal influence for the purpose of obtaining a franchise;7 or that a lease is entered into for the purpose of carrying on an illegal business.8 such as prostitution;9 or that a lease,10 or that a contract is intended to create a monopoly,11 or is in violation of the anti-trust statutes;12 that a contract to lease a railroad is illegal;13 or that a chattel mortgage14 is given to defraud creditors, does not violate the parol evidence rule and is admissible. A contract of stock subscription which is in writing may be shown by extrinsic evidence to be illegal.15

21Gandy v. Weckerly, 220 Pa. St. 285, 18 L. R. A. (N.S.) 434, 69 Atl. 858.

22Gandy v. Weckerly, 220 Pa. St. 285, 18 L. R. A. (N.S.) 434, 69 Atl. 858.

23 See Sec. 2165.

24McNight v. Parsons, 136 Ia. 390, 113 N. W. 858 [sub nomine, McKnight v. Parsons, 22 L. R. A. (N.S.) 718].

25 See Sec. 2178.

26 See Sec. 298.

27 Nelson v. Berkner, 139 Minn. 301, 166 N. W. 347.

1 United States. McMullen v. Hoffman, 174 U. S. 639, 43 L. ed. 1117 [affirming, 83 Fed. 372, 45 L. R. A. 410, 28 C. C. A. 178, which reversed 75 Fed. 547]; In re Canfield, 190 Fed. 266.

Alabama. People's Bank & Trust Co. v. Floyd, - Ala. - , 75 So. 940.

Connecticut. Smith v. David B. Crockett Co., 85 Conn. 282 39 L. R. A. (N.S.) 1148, 82 Atl. 569.

Georgia. Exchange National Bank v. Henderson, 139 Ga. 260, 51 L. R. A. (N. S.) 549, 77 S. E. 36.

Iowa. Peed v. McKee, 42 Ia. 689, 20 Am. Rep. 631; France v. Munro, 138 Ia. 1, 19 L. R. A. (N.S.) 391, 115 N. W. 577.

Kansas. Friend v. Miller, 52 Kan. 139, 39 Am. St. Rep. 340, 34 Pac. 397:

Kentucky. Wilhite v. Roberts, 34 Ky. (4 Dana) 172.

Maine. Gould v. Leavitt, 92 Me. 416, 43 Atl. 17.

Massachusetts. Sherman v. Wilder, 106 Mass. 537.

Michigan. Detroit Salt Co. v. Salt Co., 134 Mich. 103, 96 N. W. 1.

Mississippi. Yazoo & M. V. R. Co. v. Searles, 85 Miss. 520, 68 L. R. A. 715, 37 So. 939; Mitchell v. Campbell, 111 Miss. 806, 72 So. 231; Lavecchia v. Tillman, 115 Miss. 288, 76 So. 266.

Pennsylvania. Kuhn v. Buhl, 251 Pa. St. 348, 96 Atl. 977.

Rhode Island. Martin v. Clarke, 8 R. I. 389, 5 Am. Rep. 586.

Washington. Ennis v. New World Life Insurance Co., 97 Wash. 122, 165 Pac. 1091.

Wisconsin. Manufacturers' & M. Inspection Bureau v. Everwear Hosiery Co., 152 Wis. 73, 42 L. R. A. (N.S.) 847, 138 N. W. 624.

Contra, Hoefeld v. Ozello, - 111. - , 125 N. E. 5.

See also as contra, Hunter v. Byron, 92 Wash. 469, 159 Pac. 703, where, however, the real purpose of the evidence was to show that the contract was never intended to take effect as between the parties, but that it was intended to deceive third persons.

2 United States. Ringer v. Virgin Timber Co., 213 Fed. 1001; Chase & Baker Co. v. National Trust & Credit Co., 215 Fed. 633.

Alabama. Smith v. Yancey, - Ala. - , 73 So. 477.

Arkansas. Roe v. Kiser, 62 Ark. 92, 54 Am. St. Rep. 288, 34 S. W. 534.

Georgia. Dwelle v. Blackwood, 106 Ga. 486, 32 S. E. 593,

Iowa. France v. Munro, 138 Ia. 1, 19 L. R. A. (N.S.) 391, 115 N. W. 577.

Nebraska. Koehler v. Dodge, 31 Neb. 328, 28 Am. St. Rep. 518, 47 N. W. 913.

Texas. Cotton States Building Co. v. Rawlins (Tex. Civ. App.), 62 S. W. 805.

3 People's Bank & Trust Co. v. Floyd, - Ala. - , 75 So. 940; Friend v. Miller, 52 Kan. 139, 39 Am. St. Rep. 340, 34 Pac. 397.

Contra, as to a lease for the illegal sale of intoxicating liquor. Hoefeld v. Ozello, - 111. - , 125 N. E. 5.

See also, as contra, C. H. Little Co. v. Cadwell Transit Co., 197 Mich. 481, 163 N. W. 952.

4 Manufacturers' & M. Inspection Bureau v. Everwear Hosiery Co., 152 Wis. 73, 42 L. R. A. (N.S.) 847, 138 N. W. 624.

5 Smith v. David B. Crockett Co., 85 Conn. 282, 39 L. R. A. (N.S.) 1148, 82 Atl. 569.

6Exchange National Bank v. Henderson, 139 Ga. 260, 51 L. R. A. (N.S.) 549, 77 S. E. 36.

7 Obenchain v. Ransome-Crummey Co. 69 Or. 547, 138 Pac. 1078, 139 Pac. 920

8 Lavecchia v. Tillman, 115 Miss. 288, 76 So. 266.

9Mitchell v. Campbell, 111 Miss. 806, 72 So. 231.

However, it has been held that it can not be shown that a note given by a husband to his wife for her release of dower was a part of an oral contract for a collusive divorce.16