I ntentionality certain conscious mental acts must bring about unconscious mental phenomena as their effects; third (and harder to follow), an argument that the relationship of the intensity of a mental act and its concomitant mental act requires that the latter be unconscious in the case of conscious mental phenomena – the strength of the concomitant consciousness is a function of their own strength, and that, because of this relationship, in certain cases in which the latter is a positive magnitude, the former must lack a positive value Finally, an argument that accepting that there are only conscious mental acts leads to a vicious infinite regress of mental acts He sums up the last argument as follows: we could attempt to prove that the hypothesis that each mental phenomenon is an object of a mental phenomenon leads to an infinite complexity of mental states, which is both intrinsically impossible and contrary to experience (81/105) It is in response to this fourth kind of argument that Brentano formulates his ‘same-order’ view of consciousness One can summarize the dialectic as follows: [i] If there are no unconscious mental states, then all mental states are conscious, i.e all mental states are the objects of mental states (This follows from Brentano’s understanding of the word ‘consciousness’.) [ii] Prima facie objection: if all mental states are conscious, then there is a vicious regress of mental states Brentano uses hearing, the presentation of a sound, to illustrate the prima facie threat of a vicious regress If no mental phenomenon is possible without a correlative consciousness of it, then, along with the hearing, the presentation of a sound, we have to have a presentation of the hearing, i.e a presentation of the presentation of the sound But then it looks as if the presentation of the presentation of the sound must be accompanied by a presentation of it in turn So now we have three presentations: the presentation of the sound, the presentation of the presentation of the sound, and the presentation of the presentation of the presentation of the sound Either the series will be infinite or it will terminate in an unconscious presentation (The higher-order view avoids this regress by accepting unconscious mental states at the second-order.) If one denies that there are unconscious presentations, one seems committed to an infinite number of mental acts even for the simplest act of hearing [iii] Same-order response to prima facie objection: the consciousness necessary to make a mental phenomenon conscious is built into the mental phenomenon itself 221