“'Stare decisis' is usually the wise policy.... [b]ut where correction through legislative action is practically impossible, this Court has often overruled its earlier decisions...”

What Brandeis means is that courts should not just decide cases based upon past court precedents but to judge the matter afresh and in accordance with the law as it is written. This is particularly important for Constitutional issues -- just because of one poor court decision does not mean that all future cases must be decided as the previous one.