|Doctoral advisor||Bernard Williams|
|philosophy of mind, philosophy of action, feminist philosophy|
Jennifer Hornsby, FBA (born 1951) is a British philosopher with interests in the philosophies of mind, action, language, as well as feminist philosophy. She is currently a professor at the School of Philosophy, Birkbeck, University of London. She is well known for her opposition to orthodoxy in current analytic philosophy of mind, and for her use of J. L. Austin's Speech Act Theory to look at the effects of pornography.
Hornsby earned her PhD from the University of Cambridge under the direction of Bernard Williams. She also earned a BA and MPhil from Oxford and London, respectively. She taught at the University of Oxford for 17 years before moving to Birkbeck College, London. She was president of the Aristotelian Society from 1996 to 1997.
Hornsby's work focuses primarily on the philosophies of mind, action, language, and feminist philosophy.
Hornsby's action theory is significantly influenced by the philosophy of Donald Davidson. In her book Actions (1980), she argues that actions are events occurring beneath the surface of the skin. The argument for this turns on an ambiguity in the slogan "all actions are bodily movements". The ambiguity stems from the fact that 'move' is one of a class of verbs that can occur either transitively or intransitively. Nominal expressions containing such verbs are therefore ambiguous: for example, 'the movement of the flag' can refer either to the action of someone's moving the flag or to the resultant movement of the flag. As we only ever answer a question about what someone did by using transitive verbs --- e.g. 'Jack moved his arm', not 'Jack's arm moved' (unless the latter is taken to imply that the former is true) --- the slogan "all actions are bodily movements" is only true if 'movement' is read transitively. This ambiguity noted, Hornsby then points out that if A VT-s B, then A caused B to VI ('T' and 'I' serving to distinguish between transitive and intransitive uses of the relevant verbs). If Jack raisedT the flag, Jack caused the flag to riseI. As causes and effects must be distinct, we must therefore also distinguish between Jack's raisingT his arm from Jack's arm's risingI, the former causing the latter. So actions are bodily movementsT, which cause bodily movementsI. The final move is to claim that we know from physiology that the causes of bodily movementsI are events that occur beneath the surface of the skin. Therefore, actions occur beneath the surface of the skin.
This claim is combined with another: that the most basic description, in the causal sense of 'basic', of an action is as a trying. This arises from accepting a coarse-grained account of the individuation of events, according to which events are particulars that can be described in many different ways. The descriptions are distinguished by the effects of the described event in terms of which they are picked out. For example, the event of my slamming the door may be identical to the event of my waking the cat. The first description picks out the event by reference to the event of the door's being slammed. The second description picks out the event by reference to the event of the cat's waking. The question then is, Is there a description of the events which are actions that picks them out without reference to any effects? Hornsby's answer is that we can describe actions as tryings. I can try to raise my arm and, if successful, my arm will rise. (Note, though, that not all tryings are actions, only the successful ones.)
Hornsby is a member of the Norwegian Academy of Science and Letters. In July 2017, she was elected a Fellow of the British Academy (FBA), the United Kingdom's national academy for the humanities and social sciences. She was elected international honorary member of the American Academy of Arts & Sciences in April 2018.