 Brentano takes it to be beyond doubt that such a perception is a judgement, only not a predicative one. This is controversial. For example, Brentano’s modus ponens is Moritz Schlick’s (1925, 80/1974, 87) modus tollens: perception is not judgement, hence, a perception cannot be knowledge. So why should one think of seeing a yellow canary or hearing a sound as a judgement in the first place? Consider again your perception of the yellow canary. The canary looks different from its surroundings to you and you can train your attention on it. In this situation you will, to use a non-committal phrase, “take the canary to be real”. Seeing the canary is a particular kind of “taking the canary to be”, namely as something real; in Brentano’s terminology that is “an acknowledging of the canary”. If this is right, there are judgements that do not predicate any properties of an object and merely acknowledge it.