note: you choose the argument.  It may be either

• an argument of a particular philosopher (in which case you must carefully read what he or she actually said or wrote: e.g. Descartes's argument about dreaming in the First Meditation)
• a type of argument which you have come across (in which case, you must lay out its structure as clearly as possible: e.g. the "Argument from Illusion")
• an argument you have thought of for yourself (in which case, again, you should lay it out clearly, and try hard to think of and if possible to answer possible objections to it)