Affirming the consequent is a logical fallacy that occurs when someone assumes that if a condition leads to a certain outcome, then the presence of that outcome must mean the condition is true. For example, if we say, "If it rains, the ground will be wet," and then observe that the ground is wet, concluding that it must have rained is an example of this fallacy. This reasoning is flawed because there could be other reasons for the ground being wet, such as a sprinkler system or spilled water. Thus, affirming the consequent overlooks alternative explanations and leads to incorrect conclusions.