delivered the opinion of the Court.
This case touches a sensitive and important area of human rights. Oklahoma deprives certain individuals of a right which is basic to the perpetuation of a race—the right to have offspring. Oklahoma has decreed the enforcement of its law against petitioner, overruling his claim that it violated the Fourteenth Amendment. Because that decision raised grave and substantial constitutional questions, we granted the petition for certiorari.
The statute involved is Oklahoma’s Habitual Criminal Sterilization Act. Okla. Stat. Ann. Tit. 57, § § 171, et seq.; L. 1935, pp. 94 et seq. That Act defines an “habitual criminal” as a person who, having been convicted two or more times for crimes “amounting to felonies involving moral turpitude,” either in an Oklahoma court or in a court of any other State, is thereafter convicted of such a felony in Oklahoma and is sentenced to a term of imprisonment in an Oklahoma penal institution. § 173. Machinery is provided for the institution by the Attorney General of a proceeding against such a person in the Oklahoma courts for a judgment that such person shall be rendered sexually sterile. §§ 176, 177. Notice, an opportunity to be heard, and the right to a jury trial are provided. § § 177-181. The issues triable in such a proceeding are narrow and con*537fined. If the court or jury finds that the defendant is an “habitual criminal” and that he “may be rendered sexually sterile without deteriment to his or her general health,” then the court “shall render judgment to the effect that said defendant be rendered sexually sterile” (§ 182) by the operation of vasectomy in case of a male, and of salpingectomy in case of a female. § 174. Only one other provision of the Act is material here, and that is § 195, which provides that “offenses arising out of the violation of the prohibitory laws, revenue acts, embezzlement, or political offenses, shall not come or be considered within the terms of this Act.”
Petitioner was convicted in 1926 of the crime of stealing chickens, and was sentenced to the Oklahoma State Reformatory. In 1929 he was convicted of the crime of robbery with firearms, and was sentenced to the reformatory. In 1934 he was convicted again of robbery with firearms, and was sentenced to the penitentiary. He was confined there in 1935 when the Act was passed. In 1936 the Attorney General instituted proceedings against him. Petitioner in his answer challenged the Act as unconstitutional by reason of the Fourteenth Amendment. A jury trial was had. The court instructed the jury that the crimes of which petitioner had been convicted were felonies involving moral turpitude, and that the only question for the jury was whether the operation of vasectomy could be performed on petitioner without detriment to his general health. The jury found that it could be. A judgment directing that the operation of vasectomy be performed on petitioner was affirmed by the Supreme Court of Oklahoma by a five to four decision. 189 Okla. 235, 115 P. 2d 123.
Several objections to the constitutionality of the Act have been pressed upon us. It is urged that the Act cannot be sustained as an exercise of the police power, in view *538of the state of scientific authorities respecting inheritability of criminal traits.1 It is argued that due process is lacking because, under this Act, unlike the Act2 upheld in Buck v. Bell, 274 U. S. 200, the defendant is given no opportunity to be heard on the issue as to whether he is the probable potential parent of socially undesirable offspring. See Davis v. Berry, 216 F. 413; Williams v. Smith, 190 Ind. 526, 131 N. E. 2. It is also suggested that the Act is penal in character and that the sterilization provided for is cruel and unusual punishment and violative of the Fourteenth Amendment. See Davis v. Berry, supra. Cf. State v. Feilen, 70 Wash. 65, 126 P. 75; Mickle v. Henrichs, 262 F. 687. We pass those points without intimating an opinion on them, for there is a feature of the Act which clearly condemns it. That is, its failure to meet the requirements of the equal protection clause of the Fourteenth Amendment.
We do not stop to point out all of the inequalities in this Act. A few examples will suffice. In Oklahoma, grand larceny is a felony. Okla. Stats. Ann. Tit. 21, §§ 1705, 5. Larceny is grand larceny when the property taken exceeds $20 in value. Id. § 1704. Embezzlement is punishable “in the manner prescribed for feloniously stealing property of the value of that embezzled.” Id. § 1462. Hence, he who embezzles property worth more than $20 is guilty of a felony. A clerk who appropriates over $20 from his employer’s till (id. § 1456) and a stranger who steals the same *539amount are thus both guilty of felonies. If the latter repeats his act and is convicted three times, he may be sterilized. But the clerk is not subject to the pains and penalties of the Act no matter how large his embezzlements nor how frequent his convictions. A person who enters a chicken coop and steals chickens commits a felony (id. § 1719); and he may be sterilized if he is thrice convicted. If, however, he is a bailee of the property and fraudulently appropriates it, he is an embezzler. Id. § 1455. Hence, no matter how habitual his proclivities for embezzlement are and no matter how often his conviction, he may not be sterilized. Thus, the nature of the two crimes is intrinsically the same and they are punishable in the same manner. Furthermore, the line between them follows close distinctions—distinctions comparable to those highly technical ones which shaped the common law as to “trespass” or “taking.” Bishop, Criminal Law (9th ed.) Vol. 2, §§ 760, 799, et seq. There may be larceny by fraud rather than embezzlement even where the owner of the personal property delivers it to the defendant, if the latter has at that time “a fraudulent intention to make use of the possession as a means of converting such property to his own use, and does so convert it.” Bivens v. State, 6 Okla. Cr. 521, 529, 120 P. 1033, 1036. If the fraudulent intent occurs later and the defendant converts the property, he is guilty of embezzlement. Bivens v. State, supra; Flohr v. Territory, 14 Okla. 477, 78 P. 565. Whether a particular act is larceny by fraud or embezzlement thus turns not on the intrinsic quality of the act but on when the felonious intent arose— a question for the jury under appropriate instructions. Bivens v. State, supra; Riley v. State, 64 Okla. Cr. 183, 78 P. 2d 712.
It was stated in Buck v. Bell, supra, that the claim that state legislation violates the equal protection clause of the Fourteenth Amendment is “the usual last resort of constitutional arguments.” 274 U. S. p. 208. Under our con*540stitutional system the States in determining the reach and scope of particular legislation need not provide “abstract symmetry.” Patsone v. Pennsylvania, 232 U. S. 138, 144. They may mark and set apart the classes and types of problems according to the needs and as dictated or suggested by experience. See Bryant v. Zimmerman, 278 U. S. 63, and cases cited. It was in that connection that Mr. Justice Holmes, speaking for the Court in Bain Peanut Co. v. Pinson, 282 U. S. 499, 501, stated, “We must remember that the machinery of government would not work if it were not allowed a little play in its joints.” Only recently we reaffirmed the view that the equal protection clause does not prevent the legislature from recognizing “degrees of evil” (Truax v. Raich, 239 U. S. 33, 43) by our ruling in Tigner v. Texas, 310 U. S. 141, 147, that “the Constitution does not require things which are different in fact or opinion tobe treated in law as though they were the same.” And see Nashville, C. & St. L. Ry. v. Browning, 310 U. S. 362. Thus, if we had here only a question as to a State’s classification of crimes, such as embezzlement or larceny, no substantial federal question would be raised. See Moore v. Missouri, 159 U. S. 673; Hawker v. New York, 170 U. S. 189; Finley v. California, 222 U. S. 28; Patsone v. Pennsylvania, supra. For a State is not constrained in the exercise of its police power to ignore experience which marks a class of offenders or a family of offenses for special treatment. Nor is it prevented by the equal protection clause from confining “its restrictions to those classes of cases where the need is deemed to be clearest.” Miller v. Wilson, 236 U. S. 373, 384. And see McLean v. Arkansas, 211 U. S. 539. As stated in Buck v. Bell, supra, p. 208, “. . . the law does all that is needed when it does all that it can, indicates a policy, applies it to all within the lines, and seeks to bring within the lines all similarly situated so far and so fast as its means allow.”
*541But the instant legislation runs afoul of the equal protection clause, though we give Oklahoma that large deference which the rule of the foregoing cases requires. We are dealing here with legislation which involves one of the basic civil rights of man. Marriage and procreation are fundamental to the very existence and survival of the race. The power to sterilize, if exercised, may have subtle, far-reaching and devastating effects. In evil or reckless hands it can cause races or types which are inimical to the dominant group to wither and disappear. There is no redemption for the individual whom the law touches. Any experiment which the State conducts is to his irreparable injury. He is forever deprived of a basic liberty. We mention these matters not to reexamine the scope of the police power of the States. We advert to them merely in emphasis of our view that strict scrutiny of the classification which a State makes in a sterilization law is essential, lest unwittingly, or otherwise, invidious discriminations are made against groups or types of individuals in violation of the constitutional guaranty of just and equal laws. The guaranty of “equal protection of the laws is a pledge of the protection of equal laws.” Yick Wo v. Hopkins, 118 U. S. 356, 369. When the law lays an unequal hand on those who have committed intrinsically the same quality of offense and sterilizes one and not the other, it has made as invidious a discrimination as if it had selected a particular race or nationality for oppressive treatment. Yick Wo v. Hopkins, supra; Gaines v. Canada, 305 U. S. 337. Sterilization of those who have thrice committed grand larceny, with immunity for those who are embezzlers, is a clear, pointed, unmistakable discrimination. Oklahoma makes no attempt to say that he who commits larceny by trespass or trick or fraud has biologically inheritable traits which he who commits embezzlement lacks. Oklahoma’s line between larceny by fraud and embezzlement is determined, as we have noted, “with reference to the time when the *542fraudulent intent to convert the property to the taker's own use” arises. Riley v. State, supra, 64 Okla. Cr. at p. 189, 78 P. 2d p. 715. We have not the slightest basis for inferring that that line has any significance in eugenics, nor that the inheritability of criminal traits follows the neat legal distinctions which the law has marked between those two offenses. In terms of fines and imprisonment, the crimes of larceny and embezzlement rate the same under the Oklahoma code. Only when it comes to sterilization are the pains and penalties of the law different. The equal protection clause would indeed be a formula of empty words if such conspicuously artificial lines could be drawn. See Smith v. Wayne Probate Judge, 231 Mich. 409, 420-421, 204 N. W. 40. In Buck v. Bell, supra, the Virginia statute was upheld though it applied only to feeble-minded persons in institutions of the State. But it was pointed out that “so far as the operations enable those who otherwise must be kept confined to be returned to the world, and thus open the asylum to others, the equality aimed at will be more nearly reached.” 274 U. S. p. 208. Here there is no such saving feature. Embezzlers are forever free. Those who steal or take in other ways are not. If such a classification were permitted, the technical common law concept of a “trespass” (Bishop, Criminal Law, 9th ed., vol. 1, §§ 566, 567) based on distinctions which are “very largely dependent upon history for explanation” (Holmes, The Common Law, p. 73) could readily become a rule of human genetics.
It is true that the Act has a broad severability clause.3 But we will not endeavor to determine whether its applica*543tion would solve the equal protection difficulty. The Supreme Court of Oklahoma sustained the Act without reference to the severability clause. We have therefore a situation where the Act as construed and applied to petitioner is allowed to perpetuate the discrimination which we have found to be fatal. Whether the severability clause would be so applied as to remove this particular constitutional objection is a question which may be more appropriately left for adjudication by the Oklahoma court. Dorchy v. Kansas, 264 U. S. 286. That is reemphasized here by our uncertainty as to what excision, if any, would be made as a matter of Oklahoma law. Cf. Smith v. Cahoon, 283 U. S. 553. It is by no means clear whether, if an excision were made, this particular constitutional difficulty might be solved by enlarging on the one hand or contracting on the other (cf. Mr. Justice Brandeis dissenting, National Life Ins. Co. v. United States, 277 U. S. 508, 534-535) the class of criminals who might be sterilized.
Reversed.
Healy, The Individual Delinquent (1915), pp. 188-200; Sutherland, Criminology (1924), pp. 112-118, 621-622; Gillin, Criminology and Penology (1926), e. IX; Popenoe, Sterilization and Criminality, 53 Rep. Am. Bar. Assoc. 575; Myerson et al., Eugenical Sterilization (1936), c. VIII; Landman, Human Sterilization (1932), c. IX; Summary of the Report of the American Neurological Association Committee for the Investigation of Sterilization, 1 Am. Joum. Med. Jur. 253 (1938).
And see State v. Troutman, 50 Ida. 673, 299 P. 668; Chamberlain, Eugenics in Legislatures and Courts, 15 Am. Bar Assn. Journ. 165; Castle, The Law and Human Sterilization, 53 Rep. Am. Bar Assoc., 556, 572; 2 Bill of Rights Review 54.
Sec. 194 provides:
“If any section, sub-section, paragraph, sentence, clause or phrase of this Act shall be declared unconstitutional, or void for any other reason by any court of final jurisdiction, such fact shall not in any manner invalidate or affect any other or the remaining portions of this Act, but *543the same shall continue in full force and effect. The Legislature hereby declares that it would have passed this Act, and each section, subsection, paragraph, sentence, clause or phrase thereof, irrespective of the fact that any one or more other sections, sub-sections, paragraphs, sentences, clauses or phrases be declared unconstitutional.”