I am a Jacobsen Research Fellow in Philosophy at the London School of Economics and the University of London Institute of Philosophy.  From September 2008 I will be teaching at the University of Stirling.  My research interests include the history of early analytic philosophy, the philosophy of logic and language and the philosophy of the later Wittgenstein.  The following link to some recent papers of mine:

Tractarian Objects and Logical Categories (forthcoming in Synthese (online first version))

Symbols in Wittgenstein's Tractatus (European Journal of Philosophy (2007) 15(3): 367-394 (published version))

Email: colin.johnston_at_sas.ac.uk