Supreme Court of Delaware
 44 Del. 262,  65 A.2d 489 (1949)

 [p. 266] PEARSON, Judge, delivering the opinion of the court:

 The defendant Long was married to his first wife in Wilmington, and resided there with her for thirty years prior to their separation in October 1945.  On September 21, 1946, he went to Arkansas.  He had been pensioned from the police force, and had been in bad health for a number of years.  He testified that he went to Arkansas on account of his health because he 'thought it would be a better climate'; also that he went there to obtain a divorce; and that he intended 'to leave Delaware permanently and take up a permanent domicile in Arkansas'.  His health improved there.  He returned to Wilmington for a few days in November 'for business reasons' and spent the Christmas holidays in Wilmington.  On December 3, he renewed his Delaware automobile registration for six months ending June 30, 1947.  He remained in Arkansas for the statutory period of residence required for divorce in that state, and instituted divorce proceedings against his wife in the Chancery Court of Garland County.  On January 7, 1947, that court entered a decree of absolute divorce.  The decree recites publication of a notice and the mailing of a registered letter with a copy of the complaint to defendant's wife, a nonresident of Arkansas.  She did not appear in the proceeding.  She testified before the lower court here that she was not 'served with any divorce papers' and did not receive any mail or a registered letter from Arkansas.  On the same day the divorce decree was granted, defendant left Arkansas and returned to Wilmington where he has since resided.  While in Wilmington during the Christmas holidays of 1946, he had been offered a job in a hospital there.  He accepted this job after the divorce decree was granted and began work on January 13, 1947.  On January 25, he was married to a second wife in Wilmington.  This marriage was the subject of the bigamy prosecution under Rev.Code of Del. Sec. 5254.  Defendant contends that the court [p. 267] below was required to recognize the Arkansas decree [and] that the court erred in excluding evidence of a reasonable mistake by defendant in the application of law to the facts, and in rejecting other testimony.

* * *

 [E]rror is assigned for the refusal of the lower court to receive evidence relating . . . to defendant's mistake in applying [p. 275] law to the facts with respect to the validity of the Arkansas divorce.  In his brief, defendant makes the following statement of facts in this connection:

 'Prior to the defendant's decision to go to Arkansas he discussed the question of securing a divorce with a Delaware attorney (not his present attorney). Shortly prior to that time he had been advised by certain men, * * * that they had lived in adultery with defendant's wife.  The evidence would have borne out these facts and shown with specificity by the men themselves that they had registered at certain Wilmington hotels and the names under which they had registered and that sexual relations were had.  These facts were known to the Delaware attorney.  In his discussion with the Delaware attorney he stated he was 'fed up with Wilmington' and that his health had been bad and that he wanted to get away.  He also stated, upon being advised that he could get a divorce in Delaware, that he did not want to further embarrass his children by getting a divorce on the ground of adultery, especially since a number of them had just come out of the service and were attempting to make their way in Wilmington.

 'He was advised by the Delaware attorney to go to Arkansas for the divorce and that it would be 'just as good as if obtained in Delaware.'  He was advised and knew that he could secure a divorce in Delaware for approximately one-tenth of the total cost in Arkansas.  * * *

 '* * * After he had returned from Arkansas he decided to remarry, which marriage is the basis for the present prosecution.  Before deciding on marriage, he went to the same Delaware attorney and inquired whether he was free to remarry and whether the divorce was good in view of the fact that he had returned to Delaware and changed his intention of living in Arkansas for an indefinite period of time.  He was advised that the divorce was good and that [p. 276] he was free to remarry.  He then made arrangements with the Reverend Harris for the marriage.  Reverend Harris, due to hearsay statements he had read in the newspapers, was suspicious of the validity of the divorce in Arkansas.  The Reverend Harris decided, after conferring with the defendant, to visit the Delaware attorney himself and, upon doing so, was advised that the divorce was good and the defendant was free to remarry.

 'The defendant conferred a final time with his attorney before applying for a marriage application and defendant's Delaware counsel appeared with him and signed his second marriage application as guarantor in the Office of the Clerk of the Peace for New CastleCounty.  He also offered evidence to the Clerk of the Peace that he was legally divorced and free to remarry.'

* * *

 The evidence of defendant's consulting an attorney and following his advice was refused on two grounds:  (1) that it is 'not proper to presume, in view of the bigamy statute and the exceptions thereto that our Legislature intended that other and additional exceptions be extended by the Courts of this State'; and (2) that defendant's mistake was one of law, and is a case 'to which the maxim 'ignorantia juris [p. 277] non excusat' applies.' Numerous authorities are cited by the court.

  Taking up the first ground, the statute defining the crime of bigamy provides, Rev.Code, § 5254:  'Bigamy; Penalty; Inhabitant Going Out of State and Contracting Marriage With Intent to Return, Contrary to This Section, Liable to Prosecution:--Whoever, having contracted marriage, shall, in the lifetime of his or her husband or wife, marry with another person, or if any unmarried person shall marry with a person having at the time a husband, or wife living, and such fact be known to such unmarried person, he or she shall be deemed guilty of bigamy, and shall be fined not less than four hundred nor more than two thousand dollars, and shall be imprisoned for not less than three months nor more than six years. * * *'

 The next section of the Code makes it a crime to cohabit after conviction of bigamy, and continues, Rev.Code, § 5255:  '* * * But no person shall be convicted of bigamy, if the husband, or wife, at the time of the second marriage, shall have been absent for five years, and during that time the accused shall have received no intelligence of his or her being alive, or if there shall have been other good ground to believe the former husband or wife dead, or if the former marriage have been legally dissolved.'

 Of course, the mere specification of certain defenses in § 5255 does not exclude all other defenses.  We can think of no sound reason why defenses of coercion and insanity, for instance, should not be available.  A recognition of mistake of fact as a defense is found in Reg v. Tolson, 23 Q.B.D. 168 (referred to by this court as 'a great leading English case' in Brown v. State, 7 Pennewill 159, 74 A. 836, 25 L.R.A.,N.S., 661). There, the defense of absence of a spouse for seven years, specified in a bigamy statute, was held not to exclude a defense of reasonable mistake of fact [p. 278] where the accused, believing erroneously but on reasonable grounds that her husband was dead, had remarried after his absence for less than seven years.  The defense of mistake of fact is important only because it negatives a 'criminal mind', general criminal intent.  Keedy:  Ignorance and Mistake in the Criminal Law, 22 Harv.Law Rev. 75, 82.  Upon considering the particular behavior defined as criminal (compare Brown v. State, supra) the specified defenses themselves, and the seriousness of the punishment provided, we accept the view that the statute does not exclude as a defense the absence of general criminal intent; that is, the intent to do what would constitute a crime if the surrounding circumstances were such as a reasonable man in the defendant's position would likely believe them to be (the criminality of the defendant's subjective state of mind being measured by an objective standard.) Compare Sayre:  The Present Signification of Mens Rea in the Criminal Law, Harvard Legal Essays (1934) 399, 413; Reg v. Tolson, supra, p. 181.

  We turn now to the ground that this is a case to which the ignorance of law maxim applies.  In many crimes involving a specific criminal intent, an honest mistake of law constitutes a defense if it negatives the specific intent.  State v. Pullen, 3 Pennewill, 184, 50 A. 538 (larceny); State v. Collins, 1 Marv. 536, 41 A. 144 (embezzlement); see list of cases in the Keedy article, supra, at p. 89; also Perkins:  Ignorance and Mistake in Criminal Law, 88 Univ. of Pa.Law Rev. 35, 45, 46.  As to crimes not involving a specific intent, an honest mistake of law is usually, though not invariably, held not to excuse conduct otherwise criminal.  (Perkins article, pp. 41-45 and cases cited.)  A mistake of law, where not a defense, may nevertheless negative a general criminal intent as effectively as would an exculpatory mistake of fact.  Thus, mistake of law is disallowed as a defense in spite of the fact that it may show an absence [p. 279] of the criminal mind. The reasons for disallowing it are practical considerations dictated by deterrent effects upon the administration and enforcement of the criminal law, which are deemed likely to result if it were allowed as a general defense.  As stated in the Perkins article, supra, p. 41:  '* * * But if such ignorance were available as a defense in every criminal case, this would be a constant source of confusion to juries, and it would tend to encourage ignorance at a point where it is peculiarly important to the state that knowledge should be as widespread as is reasonably possible.  In the language of one of the giants of the profession, this is a point at which 'justice to the individual is rightly outweighed by the larger interests on the other side of the scales."  Quoting from Holmes: The Common Law, p. 48.

  Similar considerations are involved when we disallow ignorance or mistake of law as a defense to a defendant who engages in criminal conduct (even though not obviously immoral or anti-social) where his ignorance or mistake consists merely in (1) unawareness that such conduct is or might be within the ambit of any crime; or (2) although aware of the existence of criminal law relating to the subject of such conduct, or to some of its aspects, the defendant erroneously concludes (in good faith) that his particular conduct is for some reason not subject to the operation of any criminal law.  But it seems to us significantly different to disallow mistake of law where (3) together with the circumstances of the second classification, it appears that before engaging in the conduct, the defendant made a bona fide, diligent effort, adopting a course and resorting to sources and means at least as appropriate as any afforded under our legal system, to ascertain and abide by the law, and where he acted in good faith reliance upon the results of such effort.  It is inherent in the way our legal system functions that the criminal law consequences of any [p. 280] particular contemplated conduct cannot be determined in advance with certainty.  Not until after the event, by final court decision, may the consequences be definitely ascertained.  Prior to the event, the ultimate that can be ascertained about the legal consequences consists of predictions of varying degrees of probability of eventualtion. Hence, in the sense in which we are concerned with the expression, a 'mistake of law' of the second or third classification refers to the failure of predictions of legal consequences to come to pass.  No matter how logical, plausible and persuasive may be the bases for a prediction (assumptions, abstract legal rules, reasoning, etc.,) a mistake of law arises if the prediction does not eventuate; and there is no mistake of law if the prediction eventuates.

 With these thoughts in mind, let us examine how the considerations which justify the rejection of a mistake of the first and second classifications operate with respect to a mistake of the third classification.  The objection of tending to 'encourage ignorance' of the law would hardly seem applicable. The very conditions of the third classification include a diligent effort, in good faith, by means as appropriate as any available under our legal system, to acquire knowledge of the relevant law.  The objection of difficulties of proof, including facilitation of subterfuge, is applicable, if at all, in a far less degree than in the case of mistakes of the first and second classifications.  For them, the facts are essentially confined to the defendant's subjective state of mind.  The conditions of the third classification are not so limited.  They include an affirmative showing of effort to abide by the law, tested by objective standards rather than the defendant's subjective state of mind.

 Any deterrent effects upon the administration of the criminal law which might result from allowing a mistake of the third classification as a defense seem greatly outweighed [p. 281] by considerations which favor allowing it.  To hold a person punishable as a criminal transgressor where the conditions of the third classification are present would be palpably unjust and arbitrary. Most of the important reasons which support the prohibition of ex post facto legislation are opposed to such a holding.  It is difficult to conceive what more could be reasonably expected of a 'model citizen' than that he guide his conduct by 'the law' ascertained in good faith, not merely by efforts which might seem adequate to a person in his situation, but by efforts as well designed to accomplish ascertainment as any available under our system.  We are not impressed with the suggestion that a mistake under such circumstances should aid the defendant only in inducing more lenient punishment by a court, or executive clemency after conviction.  The circumstances seem so directly related to the defendant's behavior upon which the criminal charge is based as to constitute an integral part of that behavior, for purposes of evaluating it.  No excuse appears for dealing with it piecemeal.  We think such circumstances should entitle a defendant to full exoneration as a matter of right, rather than to something less, as a matter of grace.  Unless there be aspects of the particular crime involved which give rise to considerations impelling a contrary holding,--some special, cogent reasons why 'justice to the individual is rightly outweighed by the larger interests on the other side of the scales'--a mistake of the third classification should be recognized as a defense.

 We find nothing about the crime of bigamy under our statute which calls for a contrary holding.  As previously decided, an absence of general criminal intent is a defense to this crime.  As to the acts involved in the crime, remarriage is obviously neither immoral nor anti-social in our culture.  These aspects lie in the circumstance that the defendant has a spouse living from whom a divorce has not been obtained which our courts will recognize as valid.  The [p. 282] matters to which a mistake of law might relate are legal questions concerning marriage and divorce.  It is a gross understatement to say that such questions are more frequently perplexing than obvious to a layman.  For these reasons, the defense seems appropriate and we hold it available in prosecutions for bigamy.  Compare Squire v. State, 46 Ind. 459; State v. Cain, 106 La. 708, 31 So. 300; Baker v. Sate, 86 Neb. 775, 126 N.W. 300, 27 L.R.A.,N.S., 1097.

  Here, from the evidence rejected by the lower court, the jury might have found substantially as follows:  (1) that prior to his second marriage, defendant consulted a reputable Delaware attorney for the purpose of ascertaining whether such marriage would be lawful or unlawful in Delaware, and so that he might abide by the law; (2) that the attorney advised him that the proposed remarriage would not be unlawful; (3) that he relied on this advice, honestly believing his remarriage lawful; (4) that his efforts to ascertain the law were at all times diligent and in good faith, not by way of subterfuge, and such that there was no better course for ascertaining the law than that which he followed; and hence, that he made a full disclosure to the attorney of the relevant circumstances as well as of what he proposed to do, and that he had no substantial reason to believe that the advice received was ill-founded, such as circumstances reasonably indicating that the attorney was incompetent to give advice about this matter, or had not given the question sufficient consideration, or that the advice was lacking in candor.  Assuming that the Arkansas decree be held invalid here, such findings would constitute a defense to the present charge as a mistake of law of the third classification. They would meet the test of bona fide, diligent efforts, as well designed to accomplish ascertainment of the law as any available under our system.  The conditions indicated furnish safeguards against pretext and fraud.  The defendant would have the burden of demonstrating that his [p. 283] efforts were well nigh exemplary.  It would not be enough merely for him to say that he had relied on advice of an attorney, unless the circumstances indicated that his conduct throughout in seeking to ascertain the law and in relying on advice received manifested good faith and diligence beyond reproach.  We see no occasion to assume that recognizing such a defense would foster dishonest practices among attorneys.  These might well be expected to be deterred by the availability of disciplinary measures for non-professional conduct.  Moreover, although erroneous advice might save a defendant from criminal responsibility for acts in reliance on it, the same acts would in many instances incur substantial civil responsibility and financial loss.  The risk of possible disingenuous resort to the defense does not seem to us sufficient to warrant withholding it from those acting in good faith.  Accordingly, the evidence should have been submitted to the jury under proper instructions.

 A new trial should be awarded for the reasons set forth in this opinion.

 An order accordingly will be entered.