John S. Mitchell, Executor and Devisee of Andrew Mitchell Deceased, brought a case against Robert Lenox and others to the United States Supreme Court in 1840. The dispute was over an agreement between John S. Mitchell and his brother-in-law Thomas Wylie that stated if either died without issue their estate would pass to the other's heirs or assigns. When Thomas Wylie passed away he left no children so his estate should have gone to John S. Mitchell’s heirs or assigns as per the agreement; however, it instead went into intestacy due to a lack of evidence for the contract being validly executed by both parties at its formation in 1807. The Supreme Court ruled that although there was not enough evidence for this contract being legally binding when formed, there were sufficient documents from after 1807 which proved that both parties had acted upon it as though it were valid until Thomas Wylie’s death in 1830; thus making it enforceable under Pennsylvania law despite its original invalidity at formation time due to lack of witnesses present during signing ceremony among other issues with execution process itself .

In the case of John S. Mitchell, Executor and Devisee of Andrew Mitchell Deceased v. Robert Lenox and Others, the dissenting opinion was that a court should not be able to decide on matters concerning title to land without first hearing evidence from both parties involved in the dispute. The majority opinion held that since no one had appeared for either party during trial, it was reasonable for them to assume that there were no facts or circumstances which would have changed their decision if they had heard testimony from each side. However, Justice McLean argued this assumption could lead to an unjust result as he felt it was necessary for courts to hear all relevant evidence before making a final ruling on any matter involving property rights. He believed allowing such decisions without full disclosure of all facts would leave open too much room for error and injustice against those who may not have been present at trial but still possess valid claims over disputed lands.