Why is a discretion in name only, because it can only be exercised one way?
<p>Source: pp 51-52, <em>The Rule of Law</em> (2010) by Thomas Bingham</p>

<blockquote>
  <p>But some exercises of judicial power are usually described as discretionary.<br>
  For example, while some remedies, notably damages,
           may be claimed as of right if liability and resulting damage are proved against a defendant,<br>
  others, notably an injunction,
           are discretionary in the sense that the judge is not bound to grant an injunction even if liability is proved. He has a discretion
           whether to grant one or not. But rules have grown up to direct the exercise of this discretion.<br>
  If the defendant’s conduct is shown to be unlawful,<br>
  and
           to be likely to cause harm to the claimant for which he will not be adequately compensated by damages,<br>
  and if the defendant
           appears likely to go on doing whatever it is that the claimant complains of and gives no undertaking to desist,<br>
  the judge
           is virtually bound to grant an injunction restraining the defendant from acting in that way. He has a discretion, <strong>but it is
           a discretion in name only because it can only be exercised one way.</strong></p>
</blockquote>

<p>I do not understand the bold; why can the judge's discretion be exercised only one way? Discretion can imply granting or refusing a request for an injunction? </p>

<p>I <em>think</em> that you are reading that sentence in a way the author did not intended but I admit that it is ambiguous.</p>

<p>I don't think it is intended to say that it is not discretionary because there is only one choice available to the judge rather than two (i.e. to grant or not to grant). I think it is saying that it is not discretionary because the law that has grown up around discretionary decisions are such that the judge effectively has <em>no</em> discretion (i.e. there is only one way open for her to rule).</p>

<p>The judge's so-called discretion can be exercised in one way only because, in the example given, all the factors which the judge is obliged to take into account on the question of whether to grant the injunction or not are in favour of granting the injunction while there are no factors at all which could be relied on to resist the granting of the injunction. In the example given, there is simply no evidence which would support the judge's refusal of the injunction. There has to be some material (some evidence) upon which a court can fasten in order to justify the exercise of any discretion at all.</p>

<p>This is not a formal set of rules, it's a book. When the author says "it can only be exercised one way," he means that while in theory the judge always has the power to rule either way, in practice these situations mean that a judge who doesn't grant the injunction will probably see his decision reversed. </p>

<p>Imagine someone walks up to a pedestrian, says "You never paid me for the last of the child pornography I sold you. Now die!," shoots them in the head, then notices that a uniformed police officer saw the whole thing. They drop their gun and put their hands up. Now, <em>technically</em>, the police officer has discretion on whether or not to arrest them. Police officers almost always have the authority to not make an arrest. But in practice, a police officer can't <em>not</em> arrest in that situation. Judges are less strongly bound, but it's the same idea: the judge <em>could</em> not issue it, but in practice a judge who doesn't issue the injunction will be reversed.</p>

judging