How did 'consideration' shift to signify grounds and the act of deliberation, then inducer of a grant or promise?

        The name of Consideration appears only about the beginning of the sixteenth century, and we do not know by what steps it became a settled term of art. The word
seems to have gone through the following significations :
[1.] first, contemplation in general;
[2.] then deliberate decision on a disputed question (hence the old form of judgments in
the Common Law Courts, “It is considered”) (e);
[3.] then the grounds as well as the act of deliberation; and
[4.] lastly, in particular, that which induces a grant or promise.

  1. Which semantic shift according to Typology by Blank (1999) befits “consideration” here? Specialization of meaning?

  2. I too don’t “know by what steps” signification 2 shifted to 3 and 4! Kindly expatiate the steps?

I understand signification 1, as it’s just the ordinary meaning of “consideration”! But 2 feels unintelligibly alien! 3 and 4 have semantically shifted too much for me to fill in the steps. The quote’s in the scan beneath alongside the red line.

Frederick Pollock. Principles Of Contract(1902). Page 170 printed on the paper, but digitally it appears at p. 220/400.