Appeal to Motives: It is argued that a proposition should be accepted or an action taken for the reason that those advocating it have good intentions.

Explanation:

A proposition or recommended action must be accepted or rejected based on the evidence that demonstrates that it is correct or a good idea. That the person advocating it really cares is irrelevant. Sincere people can be sincerely wrong. People sometimes get offended at the suggestion that these caring people could be wrong. This is because rather than thinking critically about the evidence, they have blindly given their trust to someone who has good intentions.

Note also, that it is not a given that they actually do have good intentions. This could just be the halo technique, where they make it appear that they care.

Examples:

(i) Example: Politicians often argue that certain bills should be passed even if there is solid evidence that they will not be effective, because the bill is intended to alleviate poverty or help the environment, etc.

(ii) "How can you object to their proposal? After all, they're for the environment."

Proof:

This is really a type of red herring. It directs attention away from the real issue. Look to see if the motivation of the people is relevant. It almost never is.