So first, if you like, they are metonymy. The changes will just be based on new distinctions that became relevant in the presentation of cases. It is always helpful to examine a good number of examples from around when the change occurs.
You will in fact see contexts where shades of "contemplation" and "inducement" are in fact both present in the same state of affairs. That is, the reasons for assuming a debt or making a grant could be of different types: there is good consideration (reason of natural affection), there is valuable consideration (reason of financial inducement), and there is reasonable consideration (logical reasoning).
Follow the context in these examples (Baker ed. Reports of Cases from the Time of Henry VIII. London: Selden Society, 2004.):
- Note the phrase "good consideration" used to discuss a feoffment made in exchange for something of value.
- Here "without consideration" could be read as "not in exchange for something of value," but also the sense of "without any good reason" adds to the rhetoric.
- Similarly, "sufficient consideration" can be read simultaneously as "in exchange for a fair price," or "for a valid reason." This is emphasized with the colorful term "naked covenant" for an agreement lacking consideration.
- Very nice example of ambiguity in this one: "various considerations" is truly ambiguous between "I changed my mind" and "Someone offered me a good price for the horses."
- Also ambiguous, but note the syntactic context "there is no consideration recited" suggests ambiguity (cf. "there is no reason given", etc.). This one is compelling to me, because imagine you are interpreting a will, and you can't tell whether the deceased was in a right state of mind when deciding to give a particular four horses away. If it was for a good reason (e.g., someone paid for them), you hold the will valid.
- In this final example, the context clearly suggests that the sense of "reason" is intended. However, the phrasing ("good and reasonable consideration") recalls that used in modern contracts ("good and valuable consideration"). Also see the explicit logic: if a statute is made for a good reason, it is held to be valid on appeal.
Si le feffmente fuit fait soullmente pur declarer son volunte ou pur auter bon consyderatyon et le feffor prist les proffyttes ceo serra voyde vers le disseisor non obstante que fuit pur bon consyderatyon et nemi pur mayntenance.
If the feoffment was made solely in order to declare his will or for some other good consideration, and the feoffor took the profits, that would be void as against the disseisor, notwithstanding that it was for good consideration and not for maintenance. (1533)
Nota, si tenaunt en taylle fait feffmente en fee sauns consyderatyon, les feffees serront seisyes al use de feffor et ses heirs et nemi al primer use.
Note that if a tenant in tail makes a feoffment in fee without consideration, the feoffees shall be seised to the use of the feoffor and his heirs and not to the first use. (1542)
Nota, si jeo covenante ove un auter per endenture que sil maryast ma fyle que adonques jeo donera a luy le maner de Dale en taylle ou en fee, sil marye ma fyle jeo sue seisi mayntenaunt a son use: issint le performance del suffycient consyderation, coment que le covenante ne fuit forsque dexecuter estate, change le use. Mes auterment est de un nude covenante, quar la le parte est myse a son action de covenante.
Note that if I covenant with another by indenture that if he will marry my daughter I will give him the manor of Dale in tail, or in fee, and he marries my daughter, I am forthwith seised to his use. Thus the performance of the sufficient consideration changes the use, even though the covenant was only to execute an estate. But it is otherwise a naked covenant, for there the party is driven to his action of covenant. (c.1540)
Issint si jeo aye iiii. chyvalles et jeo dye, Jeo don cell chivall a R., que nest donques present, et issint de chescun dez auterz chivalles, et puis devaunt lyvery fait pur diverz consyderations jeo revoca ceo done, ceo est bon.
Likewise if I have four horses and I say, 'I give this horse to R.', who is not then present, and similarly with each of the other horses, and then before delivery is made I revoke this gift for various considerations, that is good. (Lyte v. Peny; 1541)
Et issint en ceo cas, le done ne duit estre execute tanque le mariage, et auxi nest ascun consideration recite in le ple pur que le done eux avera, et avaunt le mariage le bailour ceo recoca, per que il est obone:
Likewise in this case, the gift is not to be executed until the marriage, and also there is no consideration recited in the plea why the donee should have the money, and the bailor revoked it before the marriage, and so it is good (ibid.)
le fesans dell statute de Acton Burnell come jeo entend fuit principallment pur le benefite de lez merchauntes, pur eux encorager de porter lour merchaundise en cest realme pur le proffette et commoditie de mesme le realme, quel estatute pur ceo que il fuit fait pur bon et reysonable consideration est favorablement construe en nostre livers.
the making of the Statute of Acton Burnell, as I think, was principally for the benefit of merchants, to encourage them to bring their merchandise into this realm, for the profit and commodity of the same realm, which statute---because it was made upon good and reasonable consideration---is favorably construed in our books. (Dutton v. Manley; 1544)