If we want to explain group behaviour, we are faced with the question: “What is a group?” Many answers have been given in philosophy, sociology and other disciplines. I’ll not try to evaluate them here. I want to consider a question that is relevant when we explain group actions from the perspective of analytical philosophy. Some examples of groups I am thinking of are people painting a house together, going for a walk together, a sports team, a task group, or a small company.
Although a group doesn’t have a shared intention, as we have seen in my last blog, usually it has a goal, which can be seen as the reason that brings the group members together, although it doesn’t need to be the intention that makes the group members act. It can make that people join the group.
Groups can be organised for only one task and once it has been executed, that’s it. Usually such groups are stable. Membership doesn’t change during the activity and once the task has been finished the group is dissolved. However, many groups have a longer duration: Its activity is permanent or at least it lasts quite a long time. Instances of such more or less permanent groups are sport teams and business companies. Then it often happens that members of the group have to be replaced now and then, temporarily or once and for all. Someone can become ill. Another member decides not to go on with the group. A member is replaced by someone who is more competent. And so on.
Let me take the case of the first team of a football club that wins the national cup. I call this team First Team (FT for short). Sometimes a team keeps the same core of players for years, but there are always changes from match to match and from year to year. Suppose that after fifteen years all players that once won the cup have left the team. Nevertheless it is normal to say “Finally, after fifteen years, the First Team has won the cup again”. One can say, of course, that in fact another team has won the cup and that it is not right to say that after fifteen years it was the First Team that has won the cup again, but then we have the problem to decide when the old guard (FTold) is no longer the new guard (FTnew) that wins the cup fifteen years later. Let’s say for simplicity that every year a player of FTold leaves the team and is replaced. So after eleven years FTold has become the FTnew that wins the cup again at last (I ignore the substitutes from match to match or even during a match). Then two views are possible. One is that FTnew is the same team as FTold, because it belongs to the same club, has a continuity in time with FTold, etc. The alternative view is that FTold and FTnew are different teams. But, as supposed, the change from FTold to FTnew is gradual, so when do we no longer have FTold and can we say that we have got FTnew instead? If one of the players of FTold leaves the team and is replaced, do we have then still the same team? If we say no, we have a problem, for everybody treats FTold still as the same First Team of our club. Moreover, say that the leaving player is injured and comes back after a few months, but after again a few months he leaves the team once and for all. Is it so then that we have two different teams during this period? Or is there a difference when a player leaves a team temporarily because of an injury and when he leaves it definitively? However, if we say that FTold remains the same after only one player has been replaced, then we can ask the same question, when a second player is replaced. If we say “yes” again, etc., then we have eleven new players that wins the cup after fifteen years and still we have the same team, although our view was that FTold and FTnew were different. Or must we say that we have a new team if at least half of the FTold players has been substituted? And why then just when six players have been substituted and not five or seven?
I can go on discussing this case and I can consider all kinds of variations. However, I think that the problem whether FTnew is or isn’t the same team as FTold has no solution. It is the same so for any other group in case members are replaced. I think that from one respect we can say that it’s still the same group and from another respect that a group with subsitutes is a new group, but the problem cannot be solved in a satisfactory way.My case looks like the famous case of the Ship of Theseus – already discussed by the Ancient Greeks – which is repaired continuously by taking out old planks and putting in new. Do we still have at the end the same ship or do we have a new one? This problem of gradual substitution is one of the great enigmas of philosophy that until now nobody could solve and that maybe never will be solved. A group changes and nevertheless stays the same during the years. That’s all we can say about it.