Pathos, poignancy, bathos are comparable when they denote the quality found in human situations, or especially in works of art or literature, which moves one to pity or sorrow.
Pathos is the common term in critical and literary use; because of its early and long-continued association with aesthetics it often implies the arousing of emotions which give pleasure rather than pain and it suggests the detachment of an observer rather than personal involvement in the perturbing events or situations.
Often, also, pathos implies not so much an effect produced on the person who sees, hears, or reads, as the art, device, or trick employed (as by a writer, speaker, or artist) in seeking to produce such an effect.
Poignancy is sometimes preferred by literary and art critics to pathos because it carries no suggestion of artificiality and centers the attention on the genuineness of the thing's emotional quality and of the emotions it arouses; it also specifically implies a power to pierce the mind or heart so that the reader, hearer, or observer feels acutely as well as with aesthetic pleasure the emotion aroused whether it be pity or sorrow or another overwhelming emotion.
Bathos is often applied to a false or pretentious pathos and typically implies a maudlin sentimentality so detached from reality as to arouse disgusted contempt rather than the softer emotions that it is intended to elicit. But bathos may also apply to a silly and artificially lugubrious reaction to something emotionally appealing that is akin to self-pity.