For the discerning Philosopher-for-hire, most adventures start with the negotiation of a Social Contract, which sets out a Goal for your adventure. Social Contracts can come from individuals, institutions, or can even simply be a tacit agreement between the members of your adventuring party. The GM will provide the suggestion for it, but the players can argue with the wording if they feel it is too constrictive. Whatever it is, it should leave plenty of room for maneuvering whilst it is being accomplished - you never know what you might be up against, after all.
For example, a good Goal for your Social Contract is "Find Occam's Razor" or "Solve the Village's Pedant Problem." Mentioning what you're going to take Occam's Razor once you've found it, or saying you're going to "save" the village from the Pedants, may be taking it a bit too far, even if it seems like a foregone conclusion right now.
Once agreed upon, the Goal is recorded by all characters on their character information sheet. When it's complete the adventure will be over, and all who helped attain the Goal will receive Treatise as a reward (also negotiatied when the Goal is presented).
During the Adventure, the GM may give some or all of the players additional Goals, as well. These should be written down on a separate piece of paper and revealed only after the adventure is over. In no case should they circumvent the Goal laid down for the entire group - however, they may have to do with the manner in which the Goal is attained.
If the GM wants to be really secretive about goal-giving, he should have a pad of paper ready with him, and each time he hands out a Goal he should give everyone a note (even if it is blank). This helps maintain secrecy and surprise.