Dog
Dogs provide what researchers term unconditional positive regard without cognitive assessment. The dog greets its owner identically whether that owner has achieved promotion or perpetrated fraud. This consistency offers comfort but eliminates informational value. The dog's enthusiasm signals nothing about the quality of human decisions or the likelihood of human plans succeeding.
This unconditional nature is the dog's gift and its limitation. It cannot tell you when you are wrong.
Hope
Hope, despite its abstract nature, responds to evidence-based probability assessment. Humans cannot sustain hope for genuinely impossible outcomes indefinitely; the brain's pattern-recognition systems eventually override wishful thinking. Hope calibrates, if imperfectly, to achievability. It flags which pursuits merit continued effort and which represent sunk cost fallacies demanding abandonment.
When hope persists despite contrary evidence, clinicians diagnose pathology. When it departs despite favourable conditions, they diagnose depression. Its fluctuations, frustrating though they may be, carry diagnostic information.
VERDICT
Hope provides feedback about reality, however imperfect. Dogs provide identical enthusiasm for Nobel laureates and serial killers alike.