Brentano, Franz Clemens (1838–1917)

Franz Brentano (1838–1917) is one of the most influential nineteenth-century German philosophers. Brentano’s best-known work, Psychologie vom Empirischen Standpunkt (1874), offered a new way to think about psychology: psychology is the study of mental phenomena whether there is a soul or not. Brentano provided an independent characterisation of mental phenomena by employing a concept that he found in the Aristotelian tradition: mental phenomena are those and only those that are directed on something – they have intentionality. The ‘directedness’ of the mental is conveyed by the locutions we use to speak of the mental: one wishes for something, one is afraid of something …

Brentano’s idea, often sloganised as ‘Intentionality is the mark of the mental’, specified the subject matter of psychology in a metaphysically neutral way and shaped a research programme. If directedness is distinctive of mental phenomena, then one will gain important insights into different kinds of mental phenomena by distinguishing them in terms of (1) the objects they are directed on and (2) the way in which they are directed on these objects.

A particular important application of Brentano’s research programme is consciousness. If I am conscious of hearing a note, are there two distinct mental acts: hearing and awareness of hearing? Brentano, inspired by Aristotle, answers NO. There is one mental act that is both directed on the note and itself. This thought has received renewed attention in contemporary philosophy of mind.

Brentano’s research programme has important consequences for value theory. He argues that presentations are not, while acts of love and hate as well as judgements are correct. Correctness is not truth: Brentano’s love of knowledge is neither true nor false. According to Brentano, correctness allows us to define both truth and goodness.