Friedrich Schiller wrote to Christian Gottfried Körner on December 1, 1788: "The reason for your complaints consists, it seems to me, in the forcible control your understanding imposes on the imagination ... it is not good and disadvantageous to the creative processes of the mind when the understanding examines the incoming ideas before they have, as it were, entered the gates [of the mind]. One idea in isolation may be very negligible and very strange, but perhaps it will become important through another one which follows; it may become a very serviceable member when it is connected with another idea that seems equally homely weird:—the understanding cannot judge any of this, unless it holds on to these ideas until they are judged in connection with one another. A creative mind, however, withdraws the guards before the gates; it seems to me that the ideas break in pêle-mêle and that only then the creative mind should review and judge the great mass of ideas. Hence our lamentations about barrenness ... you reject too early and separate (i.e. judge) too strictly."
In other words, don't outline too early ... and: don't ever use an outliner in collecting your ideas. Trying to force ideas into predetermined slots is counter-productive. The first step in writing should be less judgmental. Outlines come in only later in the creative process.