A thought rings true if it can be connected harmoniously with other concepts, emotions, and life experiences of given subjectivity. Thoughts can grow in space and increase in subtlety to capture more of reality and hence further understanding; otherwise they are cut off with a placeholder thought and tucked away.
A thought which itself is no longer growing or moving must be assigned a given value for it to be useful. It is this value which allows it to be compared with other thoughts and experiences, and assented to or dissented to with a judgment, or an evaluation that converts the thought into emotion and action.
We can compare this to the frozen earth, which though is actually in constant motion, is temporally continuous enough for our species and surrounding ecosystems to make sense of and act with and against.
The judged thought then is a thought which cleaves off the endless complexity of a reality that is in constant chaotic motion, and this cleaving has the benefit of forming a semantic continuity that allows action, feeling, and relation to happen, in relation to it.
The great work occupies a space somewhere between these extremes. With its sprawling scale, this collection of deep thoughts allows a freedom of movement in evaluating the realities underneath, yet it requires eventual boundaries, or the cordoning off of the endless depths of reality, to allow it to be relevant to certain affairs in a given period of space-time.
Upon cleaving this boundary, the idea in motion has initiated its birth and begun its decay.