There are some indications that the philosophy of science is reaching the age of discretion. Now, as I understand it, the age of discretion is characterized by self-examination. Youth is a period of blundering enthusiasm. But maturity demands the sobering influence of principles, perspectives and techniques. The adult must put away childish things. This does not demand the elimination of spontaneity and imagination, but it does require their chastening according to the principles of propriety. It seems time to ask ourselves whether the philosophy of science ought to be allowed henceforth just to grow, like Topsy, or whether a serious attempt ought not to be made to determine its nature and task.