What is the justification for supreme courts being able to overrule/overturn their own past decisions?
<p>It can’t overturn the constitution in most countries for example which gives the past apparent supremacy over the present. But between different eras of Supreme courts I guess the present takes precedence over the past? What is the rationale for this?</p>

<p>The House of Lords declared themselves able to depart from their own precedents in 1966, <a href="https://en.wikipedia.org/wiki/Practice_Statement" rel="nofollow noreferrer">stating</a> (emphasis added):</p>
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<p>Their Lordships regard the use of precedent as an indispensable foundation upon which to decide what is the law and its application to individual cases. It provides at least some degree of certainty upon which individuals can rely in the conduct of their affairs, as well as a basis for orderly development of legal rules.</p>
<p>Their Lordships nevertheless recognise that <b>too rigid adherence to precedent may lead to injustice in a particular case and also unduly restrict the proper development of the law</b>. They propose therefore, to modify their present practice and, while treating former decisions of this house as normally binding, to depart from a previous decision when it appears right to do so.
<p>In this connection they will bear in mind the danger of disturbing retrospectively the basis on which contracts, settlement of property, and fiscal arrangements have been entered into and also the especial need for certainty as to the criminal law.
<p>This announcement is not intended to affect the use of precedent elsewhere than in this House.
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<p>This applies equally to the Supreme Court, which has replaced the judicial functions of the Lords. The Practice Statement of 1966 itself overturned <em>London Street Tramways v London County Council</em> [1898] AC 375, in which the Lord Chancellor, Lord Halsbury, had said:</p>
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<p>A decision of this House once given on a point of law is conclusive on this House afterwards.</p>
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<p>In the modern understanding, it is in the interests of justice for the Supreme Court to always be able to say what the law is, even if that conflicts with the understanding of the past. As it is the final court of appeal, there is no other court which could review or overturn its decisions. Parliament <em>could</em>, and sometimes has, done so, but it is not always easy to express the desired effect in statutory language; and Parliament has many other demands on its time. It was felt that the court itself should be in a position to say that a past judgement was wrongly decided, or should no longer be considered binding for another reason.</p>
<p>In the Scottish tradition, this power has long been held to be inherent in that country's highest courts, the Court of Session / High Court of Justiciary. It is allied to the <em>nobile officium</em>, or equitable jurisdiction of those courts to provide a just remedy in the absence of any explicit law. Judicial precedent is not a barrier to justice either. As Lord Kames said (<em>Historical law-tracts</em>, 1758; tract 8),</p>
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<p>No defect in the constitution of a state deserves greater reproach, than the giving license to wrong without affording redress. Upon this account, it is the province, one should imagine, of the sovereign, and supreme court, to redress wrongs of every kind, where a peculiar remedy is not provided.</p>
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<p>Those courts have not held themselves to a strict idea of <em>stare decisis</em> with respect to their own decisions, feeling instead that in the interests of justice they should be able to decide what a particular case demands. John Erskine explained (<em>An institute of the law of Scotland</em>, 1773; book 1, title 1, section 47):</p>
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<p>Decisions therefore though they bind the parties litigating create no obligation on the judges to follow in the same tract if it shall appear to them contrary to law.</p>
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<p>English courts, at least once in their roughly modern shape following the reforms of the late 19th century, have taken a stricter view of precedent, in the interests of predictability. The reform of 1966 was influenced by differences between English and Scottish practice, and represents something of a course-correction away from the strict position of the prior era.</p>
<p>In terms of the present and the past, &quot;precedent&quot; doesn't precisely mean that the past wins out. It would be better to say that a past decision is <em>presumed to be right</em>, up until proved otherwise, or made obsolete by events such as the passage of new statutes. The presumption is binding on lower courts, and merely &quot;very strong&quot; for the highest court. The post-1966 position recognises that it is sometimes appropriate for the Supreme Court itself, seized of a particular case, to point out when a past decision is no longer right.</p>

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<p>I guess the present takes precedence over the past?</p>
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<p>It's not at all about whether the past or the present takes precedence.</p>
<p>Instead, it's about whether the law is <strong>case law</strong> (precedents set by courts) or <strong>legislation</strong> (law created by lawmakers e.g. Congress, Parliament etc.).</p>
<p>Courts always have the power to overturn their own decisions (or lower courts' decisions). Conversely, courts usually have no power to overturn legislation: they have to apply it as is. One notable exception to this rule is the power of <em>some</em> courts to declare legislation unconstitutional. Obviously, the Constitution itself cannot be declared so.</p>

<p>Sometimes, once a precedent is in place and utilized by lower courts for a long enough period of time, or due to other developments, it becomes clear that a past precedent was wrongly decided. Maybe it was too difficult to apply in practice leading to inconsistent application, maybe it is inconsistent with other precedents, maybe new information on the intent of the interpreted provision comes to light. The reasons could be myriad.</p>
<p>But, while a question of statutory interpretation can be corrected by the legislature, this isn't possible with respect to a question of constitutional interpretation which can only be changed by a constitutional amendment, something that in the United States at least, is exceeding difficult to do.</p>
<p>Since the only body that can correct past errors of constitutional interpretation is the Supreme Court, it needs to have the power to do so.</p>
<p>Furthermore, since it is the Supreme Court, no one is in a position to override its decision if it does rule a past precedent, and in practice, overruling past precedents is only rarely a black and white matter anyway, so it would be a practical impossibility to prevent.</p>
<p>From a legal theory perspective, the alternative would be to assert that past Supreme Courts are all infallible. But, in a system of government that does not assume that Supreme Court Justices are divinely inspired, that isn't a very attractive assumption.</p>

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